Glass fiber forming compositions

ABSTRACT

Mathematical relationship for ingredients for fiber glass compositions are used to identify properties of the glass. In particular the forming temperature and delta T. In one embodiment, the mathematical relationship of the ingredients is of a generic quaternary SiO 2 , CaO, Al 2 O 3  and MgO glass system. The relationship of SiO 2 , CaO, Al 2 O 3  and MgO of interest include RO=CaO+MgO, SiO 2 /CaO, SiO 2 /RO, SiO 2 /Al 2 O 3 ; Al 2 O 3 /CaO; SiO 2 +Al 2 O 3 ; SiO 2 —RO and Al 2 O 3 /RO or RO/Al 2 O 3  when other ingredients or components are added to the glass batch materials to alter the forming and/or liquidus temperatures of the glass, for example Na 2 O, Li 2 O, K 2 O and B 2 O 3  the following mathematical relationships are of interest, (SiO 2 +Al 2 O 3 )/(R2O+RO+B 2 O 3 ) where RO is as previously defined and R2O=Na 2 O+Li 2 O+K 2 O. Each of the compositional features of the glass identified above reflects the relative balance between the fluidity (i.e. viscosity) of the glass melt and its crystallization potential. Low boron or boron free fiber glass compositions having a low forming temperature, e.g. 1178 to 1240° C. and a delta T greater than 50° C. in order that the composition can be processed at a low temperature while reducing the possibility of devitrification of the molten glass in the bushing area during a glass fiber forming operation. Fiber glass compositions having low boron, e.g. less than 5.10 percent by weight has a low forming temperature, e.g. 1193 to 1240° C. and a delta T greater than 50° C.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/164,468, filed Jun. 6, 2002 now U.S. Pat. No. 6,962,886, which claimsbenefit of U.S. Provisional Application Nos. 60/330,178, filed Oct. 18,2001; 60/230,474, filed Sep. 6, 2000 and 60/136,538, filed May 28, 1999.U.S. patent application Ser. No. 10/363,609 is a 35 USC 371 of PCTapplication Serial No. PCT/US01/27451, filed Sep. 5, 2001 (now U.S. Pat.No. 6,818,575), which claims benefit of U.S. Provisional Application No.60/230,474, filed Sep. 6, 2000, and which is a continuation in part ofU.S. patent application Ser. No. 09/980,248, filed Nov. 28, 2001 (nowU.S. Pat. No. 6,686,304 B1), which is a 35 USC 371 of PCT applicationSer. No. PCT/US00/14155, filed May 23, 2000, and claims benefit of U.S.Provisional Application 60/136,538, filed May 28, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to glass compositions, and more particularly to(1) fiber glass compositions, and (2) mathematical relationships of theingredients of the glass compositions to identify thermal properties ofthe glass compositions e.g., forming and liquidus temperatures with anacceptable temperature difference to prevent devitrification of themolten glass during forming of glass fibers.

2. Discussion of the Technology

In the art of forming glass fibers it is recognized that the differencebetween the forming temperature and liquidus temperature is maintainedat a value to prevent devitrification of the molten glass during fiberforming. For example, the most common glass composition for makingcontinuous glass fiber strands for textiles and glass fiberreinforcements is known in the trade as “E glass”. The requirements asto what type of composition constitutes an E-glass composition areincluded in ASTM D578-00. An advantage of using E-glass having 6–10percent by weight B₂O₃ is that its liquidus temperature is well belowits forming temperature, i.e. typically greater than 56° C. (100° F.)and usually in the range of 83 to 111° C. (150 to 200° F.). As usedherein, the terms “forming temperature”, “T_(FORM)”, “log 3 formingtemperature” and “log 3 FT” mean the temperature of the glass at whichthe viscosity of the glass is log 3, or 1000 poise, and the terms“liquidus temperature”, “liquidus T” and “T_(LIQ)” mean the temperatureat which the solid phase (crystals) and liquid phase (melt) of the glassare in equilibrium. The difference between T_(FORM) and T_(LIQ),referred to herein as “delta T” or “ΔT”, is a common measure of thecrystallization potential of a given melt composition. The lower the ΔT,in other words the smaller the difference between the formingtemperature and the liquidus temperature, the greater thecrystallization potential. In the glass fiber forming industry, ΔT istypically maintained at a temperature of at least 50° C. (90° F.) inorder to prevent devitrification of the molten glass during a glassfiber forming operation, in particular, in the bushing area.

It is appreciated by those skilled in the art of forming glass fibers,that it is desirable to operate the glass fiber forming operation at lowtemperatures because operating the glass fiber forming operation at hightemperatures results in high-energy usage, along with associatedhigh-energy costs. In addition, the high temperatures acceleratedegradation of the refractories used in the glass melting furnace, aswell as the bushings used to form the fibers. The bushings includeprecious metals that cannot be recovered from the glass as the bushingswear.

It is recognized that boron and fluorine in addition to contributing tothe electrical properties of the E-glass, e.g. dissipation factor anddielectric constant, also lower the forming and liquidus temperatures ofthe glass while providing a ΔT of at least 50° C. (90° F.). The boron inthe form of an oxide and fluorine in the form of a fluoride are includedin the glass batch materials and act as fluxes during the glass meltingoperation. E-glass can include up to 10 wt % B₂O₃ and up to 1.0 wt %fluoride (see ASTM D 578-00 §4.2). Although the boron effectively lowersthe forming and liquidus temperatures while providing an acceptable ΔTvalue and the fluoride or fluorine acts as a flux, there are drawbacks.More particularly, these materials volatilize during melting and movewith the exhaust gases into the exhaust system. If the boron andfluorine in the exhaust gases are not removed they are released to theatmosphere. Since boron and fluorine are considered pollutants, theseemissions are closely controlled by environmental regulations, which inturn require careful control of the furnace operations and/or the use ofcostly additional pollution control equipment. In response to theseconcerns, the boron and/or fluorine content in E-glasses were reduced.For example, U.S. Pat. Nos. 4,542,106 and 5,789,329 and WO 99/12858disclose boron free or low boron e.g. 1.8 wt % glasses having a formingtemperature in the range of about 1258 to 1263° C. As can be appreciatedby those skilled in the art of glass making, reducing or removing theboron and/or fluorine content in the batch materials raises the formingtemperature. More particularly, the silica content increases as theboron content decreases, resulting in an increase in the formingtemperature. As mentioned above, increasing the forming temperatureresults in high-energy usage, high-energy costs, and acceleration of thedegradation of furnace refractories and bushings used to form thefibers.

For additional information concerning glass compositions and methods forfiberizing the glass composition, see K. Loewenstein, The ManufacturingTechnology of Continuous Glass Fibres, (3d Ed. 1993) at pages 30–44,47–60, 115–122 and 126–135, and F. T. Wallenberger (editor), AdvancedInorganic Fibers: Processes, Structures, Properties, Applications,(1999) at pages 81–102 and 129–168, which documents are herebyincorporated by reference.

In general, glass compositions having particular properties, e.g.forming temperature and delta T are identified by weight percent and/ormolar percent of the components or ingredients in the glass. As can beappreciated by those skilled in the art of glass making and/or glassfiber forming, it would be advantageous to identify the performance ofthe glass compositions not only by the amount of a particular ingredientin the glass but also by a relationship, e.g. a mathematicalrelationship of the ingredients in the glass. WO 01/32576A1 disclosesfiber glass compositions and the mathematical relationship of several ofthe ingredients, e.g. the combined Wt % of CaO and MgO, and the ratio ofAl₂O₃/CaO, in the glass. Using the combination of glass ingredients,e.g. the absolute weight percent of silica with the relationship ofother ingredients in the glass, e.g. the ratio of silica to RO (combinedWt % of CaO and MgO) would provide information regarding the meltproperties of the glass.

SUMMARY OF THE INVENTION

The present invention provides a low boron containing or a boron freeglass fiber forming composition that has a forming temperature of nogreater than 1240° C. (2262° F.), a ΔT of at least 50° C. (90° F.), andone or more or all of the following compositional features:

a ratio of SiO₂ to RO (i.e. CaO+MgO) in the range of 1.9 to 2.55;

a ratio of SiO₂ to CaO in the range of 2.1 to 2.8;

a ratio of SiO₂ to Al₂O₃ in the range of 3.7 to 5.0;

a ratio of Al₂O₃ to CaO in the range of 0.5 to 0.6;

a sum of SiO₂ and Al₂O₃ in the range of 66.0 to 73.7 wt %;

a ratio of (SiO₂+Al₂O₃) to (R₂O+RO+B₂O₃) in the range of 2.0 to 3.0;

a ratio of Al₂O₃ to RO in the range of 0.4 to 0.6; and

a difference between SiO₂ and RO; in the range of 26.5 to 36.6 wt %.

In one nonlimiting embodiment of the present invention, the glasscomposition further has a SiO₂ content of greater than 57 weight percentand B₂O₃ of no greater than 2 weight percent. In another nonlimitingembodiment of the invention, the SiO₂+Al₂O₃ content of the glasscomposition is less than 70 weight percent. In still another nonlimitingembodiment of the invention, the glass composition contains at least 1weight percent TiO₂.

In the discussion under Description of the Preferred Embodiments areglass compositions and mathematical relationship of different types ofglasses. One such glass composition has the following ingredients:

SiO₂ 55.70 to 59 percent by weight; Al₂O₃ 12.35 to 13.94 percent byweight; CaO 24.40 to 24.80 percent by weight; MgO 2.55 to 2.80 percentby weight; TiO₂ 0.05 to 0.55 percent by weight; Na₂O 0.40 to 0.50percent by weight; K₂O 0.40 to 0.60 percent by weight; Na₂O + K₂O 0.85to 1.50 percent by weight; Fe₂O₃ 0.20 to 0.40 percent by weight, andB₂O₃ 1.25 to 1.55 percent by weight, andthe following relationship of ingredients

RO 26.25 to 27.60 wt % SiO₂/CaO 2.20 to 2.40 SiO₂/RO 2.00 to 2.20SiO₂/Al₂O₃ 3.95 to 4.70 Al₂O₃/CaO 0.50 to 0.60 SiO₂ + Al₂O₃ 69.00 to70.50 wt % SiO₂ − RO 28.00 to 31.00 wt % Al₂O₃/RO 0.45 to 0.55 R2O +RO + B₂O₃ 28.90 to 30.00 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.25 to2.45 anda log 3 forming temperature in the range of 1210 to 1225° C. and ΔT isin the range of 52 to 65° C. R₂O is equal to the wt % of k₂O and Na₂O.

Reference should be made to the Description of the Preferred Embodimentsthereto for a more detailed summary of the glass compositions of theinvention and the relationship of the ingredients of the glasscompositions.

The glass compositions meeting the mathematical relationships of theinstant invention provide a glass having a forming temperature of lessthan 1240° C., preferably 1205 to 1220° C., and more preferably between1211 to 1218° C. for boron free glass and more preferably between 1187to 1205° C. for boron containing glasses.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following discussion, all numbers expressing dimensions, physicalcharacteristics, and so forth, used in the specification and claims areto be understood as being modified in all instances by the term “about”.Accordingly, unless indicated to the contrary, the numerical values setforth in the following specification and claims can vary depending uponthe desired properties obtained by the practice of the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques. Moreover, all ranges disclosed herein are to be understoodto encompass any and all subranges subsumed therein. For example, astated range of 1 wt % to 10 wt % should be considered to include anyand all subranges between (and inclusive of) the minimum value of 1 andthe maximum value of 10; that is, all subranges beginning with a minimumvalue of 1 or more and ending with a maximum value of 10 or less, e.g.,5.5 to 10.

It should be appreciated that, unless otherwise indicated, all numericalvalues discussed herein, such as but not limited to weight percent ofmaterials or temperatures, are approximate and are subject to variationsdue to various factors well known to those skilled in the art such as,but not limited to, measurement standards, equipment and techniques. Asa result, such values are to be understood as being modified in allinstances by the term “about”. Accordingly, unless indicated to thecontrary, the numerical parameters set forth in the followingspecification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, each numerical parameter should atleast be construed in light of the number of reported significant digitsand by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any recognized deviations and/or errors are discussed. Anynumerical value, however, inherently contains certain errors necessarilyresulting from the standard deviation found in their respective testingmeasurements.

In the following discussion and in the claims the limits of defining therange are included in the range. For example and not limiting to thediscussion, “in the range of 1230 to 1240° C.” and “in the range ofequal to and greater than 1230° C. and equal to and less than 1240° C.”define the same range. Further in the preceding discussion, in thefollowing discussion and in the claims, the terms “weight percent”, “wt%” and “percent by weight” are used herein interchangeably.

In one embodiment of the present invention, the mathematicalrelationships of the ingredients of a generic quaternary glass systemare disclosed. The quaternary system includes SiO₂, CaO, Al₂O₃ and MgO.As can be appreciated by those skilled in the art of making glass, inparticular making glass fibers, MgO if not added to the batch materialsis found in the batch materials as a tramp material, e.g. MgO is foundin clay at 0.3 to 0.5 percent by weight. In the practice of theinvention, MgO is added to the batch material to attain a level in theglass greater than the tramp level. The relationship of SiO₂, CaO, Al₂O₃and MgO of interest include RO=CaO+MgO, SiO₂/CaO, SiO₂/RO, SiO₂/Al₂O₃;Al₂03/CaO; SiO₂+Al₂O₃; SiO₂—RO and Al₂03/RO or RO/Al₂O₃. In the presentinvention when other ingredients or components are added to the glassbatch materials to alter the forming and/or liquidus temperatures of theglass and/or are present in the glass, for example but not limiting tothe invention Na₂O, Li₂O, K₂O and B₂O₃ the following mathematicalrelationships are of interest, (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) where RO is aspreviously defined and R2O=Na₂O+Li₂O+K₂O. In Tables 1 through 22, therelationship (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) is shown as (Si+Al)/(R2O+RO+B)to fit the formula into a reasonable column width. Each of thecompositional features of the glass identified above reflects therelative balance between the fluidity (i.e. viscosity) of the glass meltand its crystallization potential, as will be discussed below in moredetail. The physical melt properties of interest in the presentdiscussion are the forming temperature and the liquidus temperaturebecause embodiments of the present invention are to provide low boron orboron free glass compositions having a low forming temperature and adesired ΔT. In this manner, the glass can be processed, e.g. to formglass fibers at a low temperature while reducing the possibility ofdevitrification of the molten glass, e.g. in the bushing area. Withoutlimiting the present invention, one embodiment of the invention includesa glass composition having a forming temperature of no greater than1240° C. (2264° F.) and a ΔT of at least 50° C. (90° F.).

In the following discussion, the mathematical relationship is to theingredients in the glass; however, the invention is not limited theretoand contemplates identifying and using the relationship of theingredients to be added to the batch, e.g. mixing the batch prior tomelting the batch to form the glass. Further, in the followingdiscussion the mathematical relationship of the ingredients will be inwt % of the ingredients in the glass composition; however, the inventionis not limited thereto and maybe the mole % or any measurement thatidentifies the amount of the ingredient in the batch materials and/orthe glass composition.

In regards to the ingredients or constituents of the quaternary systempresented above, it is known that pure silica is the highest meltingglass former. A pure silica melt does not have a well defined meltingpoint. At 2500° C. (4532° F.), it has a viscosity of greater than aboutlog 4 (10,000) poise, and as it cools to room temperature, it graduallysolidifies and forms a glass. Pure calcia, magnesia and alumina meltsare known to have very low viscosities, e.g. in the range of 0.5–2.0poise at their respective melting points. These materials do notsolidify into a glass as the melt cools but rather crystallize instantlyat their sharply defined melting point. In a typical quaternarySiO₂—Al₂O₃—CaO—MgO glass composition with 55–60% SiO₂ and 21–26% CaO,each oxide of the quaternary system contributes its uniquecharacteristics toward its balance of melt properties.

Based on the material properties of the constituents of the quaternarysystem for a glass composition having these components, it can beinferred that as SiO₂, which is the largest oxide component of the glasscomposition in terms of weight percent, is reduced in a givencomposition of this type, the melt viscosity and the resulting log 3forming temperature drops. If CaO, which is the second largest componentof the glass composition in terms of weight percent, or MgO is increasedin such a composition, the effect of RO (CaO+MgO) on the glassproperties will be twofold. More specifically, it will not only increasethe fluidity of the resulting melt (i.e. decrease its viscosity and theforming temperature) but it will also increase the crystallizability ofthe resulting melt (i.e. increase its liquidus temperature), andtherefore reduce the ΔT.

As a result, although not required, in one nonlimiting embodiment of thepresent invention, the glass compositions have (1) the lowest SiO₂content that will yield the lowest log 3 forming temperature, which inthe present invention is below 1240° C., preferably below 1220° C. incombination with (2) the ratio of SiO₂ to RO that yields theprocess-required ΔT, which in the present invention is at least 50° C.Based on the forgoing and although not required in the practice of theinvention, in one nonlimiting embodiment of the present invention, thesilica level is preferably no greater than 62 wt % SiO₂, in order topromote a lower log 3 forming temperature. In other nonlimitingembodiments of the present invention, the glass compositions have nogreater than 60 wt % SiO₂ and no greater than 58 wt % SiO₂.

In general, MgO is included in a glass fiber forming composition becauseit has been found that the heating and melting profile of a glass fibercomposition, and in particular the liquidus temperature, can becontrolled and in particular optimized by controlling the amount of MgO.More particularly, by regulating the amount of MgO, the liquidustemperature can be selected to provide a delta T of at least 50° C. Inaddition, it has been determined that a eutectic exists in a genericquaternary SiO₂—Al₂O₃—CaO—MgO system at around 2.5–2.8 wt % MgO. For adiscussion of the eutectic reference may be had to WO 00/73231 whichdocument is hereby incorporated by reference.

The value of the SiO₂/RO ratio can be manipulated by changing the amountof SiO₂ and/or RO to produce a glass composition having a ΔT as close aspossible to the minimum desire ΔT. A decrease in the value of SiO₂/RO,which is indicative of a reduction in the wt % of SiO₂ and/or anincrease in the wt % of CaO and/or MgO, or any change or combination ofchanges in the wt % of the SiO₂, CaO and/or MgO, will effect the meltviscosity and ΔT, and will increase the crystallization potential.Conversely, an increase in the value of SiO₂/RO will effect the meltviscosity and ΔT, and will decrease the crystallization potential. Itshould be appreciated that if the value of SiO₂/RO ratio drops too low,ΔT can drop to an unacceptable level. Although not required, in onenonlimiting embodiment of the present invention, SiO₂/RO is no greaterthan 2.40. In other nonlimiting embodiments, SiO₂/RO is no greater than2.35, or no greater than 2.30, or no greater than 2.25, or no greaterthan 2.20. In still another nonlimiting embodiment of the invention, thevalue of SiO₂/RO ranges from 1.9 to 2.55, e.g. from 2.1 to 2.55 forboron-free glasses and from 1.9 to 2.4 for boron containing glasses.

In addition to the SiO₂ level and the SiO₂/RO ratio, the followingparameters also describe the compositional envelope level of aquaternary glass composition: the SiO₂/CaO ratio, the SiO₂/Al₂O₃ ratio,the Al₂O₃/CaO ratio, the sum of SiO₂+Al₂O₃, the difference betweenSiO₂—RO, and the Al₂O₃/RO ratio. The following parameters describe thecompositional envelope level of a glass composition containingadditional temperature modifying ingredients: the sum of R2O+RO+B₂O₃,where R2O=Na₂O+K₂O+Li₂O and the (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) ratio.

While the SiO₂/RO ratio at a given silica level describes thecompositional effect of RO on the crystallization potential and meltfluidity, the SiO₂/CaO ratio shows only the effect of CaO on thecrystallization potential. If the MgO and the SiO2 levels are keptconstant in a comparison of various melts, a decrease in the value ofSiO₂/CaO will show an increase in crystallization potential due to thecontribution of CaO and visa versa. The SiO₂—RO difference serves as asimilar indicator, i.e. a decrease in the difference or a smallerdifference is typically indicative of a greater relative amount of ROand thus an increase in the crystallization potential. And conversely,an increase in the difference or a larger difference in SiO₂—RO isindicative of a reduction in the crystallization potential. In onenonlimiting embodiment of the present invention, the SiO₂/CaO ratio ofthe glass composition ranges from 2.1 to 2.8, e.g. from 2.3 to 2.8 forboron-free glasses and from 2.2 to 2.7 for boron containing glasses. Inanother nonlimiting embodiment of the present invention, the SiO₂—ROdifference of the glass composition ranges from 26.5 to 36.6 wt %, e.g.from 30.5 to 36.6 wt % for boron-free glasses and from 26.5 to 34.0 wt %for boron containing glasses.

The sum of SiO₂+Al₂O₃ is another parameter that describes thecompositional envelope of a given melt. Up to about an Al₂O₃ level of 14to 15 wt %, Al₂O₃ is believed to be able to participate in the networkformation with SiO₂, and counteract the crystallization potential of ROthat is always present. At higher Al₂O₃ levels, e.g. greater than 15 wt%, Al₂O₃ will begin to act much like RO and contribute to a rise of thecrystallization potential of a given melt. Thus a lower value ofSiO₂+Al₂O₃, which is indicative of a lower Al₂O₃ level for a glasscomposition of a given wt % of SiO₂, will typically result in a lowercrystallization potential, and a greater value of SiO₂+Al₂O₃ willtypically result in a higher crystallization potential for a given melt.In one nonlimiting embodiment of the present invention, the SiO₂+Al₂O₃sum of the glass composition ranges from 66.0 to 73.7 wt %, e.g. from70.8 to 73.7 wt % for boron-free glasses and from 66.0 to 72.1 wt % forboron containing glasses.

Similarly with respect to SiO₂/Al₂O₃ and based on the characteristics ofthe melt provided by the amount of Al₂O₃, an increasing ratio valuewould be indicative of a reduction in the amount of Al₂O₃ and/or anincrease in the amount of SiO₂ and would be accompanied by a reductionin the crystallization potential of the melt. Conversely, a decreasingratio value would be accompanied by an increase in the crystallizationpotential of the melt. In one nonlimiting embodiment of the presentinvention, the SiO₂/Al₂O₃ ratio of the glass composition ranges from 3.7to 5.0, e.g. from 4.2 to 5.0 for boron-free glasses and from 3.7 to 4.9for boron containing glasses.

As mentioned above, other mathematical relationships of ingredients ofglass compositions, e.g. the Al₂O₃/CaO ratio, the Al₂O₃/RO ratio, andthe (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) ratio may be developed to characterize agiven melt. In one nonlimiting embodiment of the present invention, thevalue of the Al₂O₃/CaO ratio of the glass composition ranges from 0.5 to0.6. In another nonlimiting embodiment of the present invention, thevalue of the Al₂O₃/RO ratio of the glass composition ranges from 0.4 to0.6, e.g. from 0.46 to 0.53 for boron-free glasses and from 0.46 to 0.56for boron containing glasses. In still another nonlimiting embodiment ofthe present invention, the value of the (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) ratioof the glass composition ranges from 2.0 to 3.0, e.g. from 2.3 to 3.0for boron-free glasses and from 2.0 to 2.7 for boron containing glasses.Reference may be had to WO 01/32576 for additional discussion on theAl₂O₃/CaO ratio, and the (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) ratio.

The discussion will now be directed to additives to the batch materialsto alter the forming temperature, the liquidus temperature and the deltaT. As previously discussed, boron is a material that is added to glassfiber compositions to reduce the forming temperature and the liquidustemperature. However, as discussed earlier, the inclusion of boron oxideresults in the production of particulate emissions that, depending onthe particulate level, may have to be removed from a melting furnaceexhaust stream before being released into the environment. Although theamount of B₂O₃ can be as high as 10 wt % in an E-glass composition, inthe present invention, the glass composition has no boron or a low boroncontent, i.e. has a B₂O₃ content in the range of 0 to 5.10 wt %. Inother nonlimiting embodiments of the present invention, the glass fibercomposition has no greater than 4 wt %, or no greater than 3 wt %, or nogreater than 2 wt % B₂O₃. In another nonlimiting embodiment of thepresent invention, the glass composition is boron-free or essentiallyboron-free. As the term “essentially free” is used herein, the glasscomposition does not include an ingredient purposely added to the glassbut found in the glass in trace amounts. In the practice of theinvention, a glass having up to 0.05 wt % B₂O₃ is considered a boronfree glass.

Further, as previously discussed, fluorine is a material added to glassfiber compositions as a flux, however, because of the environmentalconcerns it is preferred not to include fluorine. Nevertheless becauseequipment is available to remove the fluorine from the exhaust gases,the invention may be practiced using fluorine. In one nonlimitingembodiment of the present invention, the glass composition has lowfluorine content, in other words, a fluorine content no greater than0.30 wt %. In another nonlimiting embodiment, the glass composition isessentially fluorine free, i.e. it includes no more than a trace amountof fluorine, which is considered herein to be up to 0.05 wt %. In stillanother nonlimiting embodiment, the glass composition does not includeany fluorine. Except where otherwise indicated, the glass fiber formingcompositions disclosed and discussed herein are essentially fluorinefree and/or do not include any fluorine.

Additional materials that can be added to the glass fiber composition tomodify the melt properties, e.g. to reduce forming temperature and/orliquidus temperature of the glass include without limiting the glasscompositions disclosed herein, are Li₂O, Na₂O, ZnO, TiO₂, MnO and/orMnO₂. Alkali oxides are network terminators and tend to effect the meltproperties. K₂O an alkali oxide is found in levels up to 0.60 wt % incommercial clays and is not normally added as a separate ingredient tothe batch materials; however, in the practice of the invention it may beadded as a separate material. In the practice of the invention alkalioxides up to 2.00 wt %, preferably 1 wt % are present in the glass ofone embodiment of the invention. In the instance where K₂O is present inthe clay, the difference is usually made up by additions of Na₂O andLi₂O. Li₂O is more effective in reducing the melt properties than Na₂O.In one non-limiting embodiment of the present invention, the glasscomposition includes 0 to 1.0 wt % Li₂O and/or 0 to 1.00 wt % Na₂Oand/or 0 to 1 wt % K₂O. Non-alkali oxide ingredients usually employed toreduce the melt properties are ZnO, TiO₂, MnO and/or MnO₂ in amounts ofabout 0 to 1.5 wt % ZnO, 0 to 1.5 wt % TiO₂, 0 to 3 wt % MnO and/or 0 to3 wt % MnO₂. It is believed that levels of these materials less than0.05 wt % would be considered either tramp amounts or so low that theywill not materially impact the glass melt properties. As a result, inanother non-limiting embodiment, 0.05 to 1.5 wt % Li₂O and/or 0.05 to1.0 wt % Na₂O and/or 0.05 to 1.0 wt % K₂O and/or 0.05 to 1.5 wt % ZnOand/or 0.05 to 1.5 wt % TiO₂ and/or 0.05 to 3 wt % MnO and/or 0.05 to 3wt % MnO₂ are included in the glass composition. In still anothernonlimiting embodiment of the invention, the glass composition includes0.2 to 1 wt % Li₂O and/or 0.30 to 1.0 wt % Na₂O and/or 0.30 to 1.0 wt %K₂O and/or 0.2 to 1 wt % ZnO and/or 0.05 to 1.1 wt % TiO₂ and/or up to 1wt % MnO and/or up to 1 wt % MnO₂.

As mentioned above, the ratio (SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) takes intoaccount the wt % of the additions of B₂O₃, Na₂O, K₂O and Li₂O that is(are) measured in the glass or batch materials regardless of the amount.Tramp amounts of these materials in the glass and/or batch are to beused to determine the value of the ratio. If any or all of the additionsof B₂O₃, Na₂O, K₂O and Li₂O are not determined to be present in theglass and/or batch, the value of zero is used for that ingredient indetermining the value of the ratio. For example but not limiting to theinvention, if Na₂O, K₂O and Li₂O are present and B₂O₃ is not, the ratio(SiO₂+Al₂O₃)/(R2$$ O+RO+B₂O₃) becomes (SiO₂+Al₂O₃)/(R2O+RO). If none ofthe ingredients B₂O₃, Na₂O, K₂O and Li₂O are determined to be present,the ratio becomes (SiO₂+Al₂O₃)/RO. In the claims when the ratio(SiO₂+Al₂O₃)/(R2O+RO+B₂O₃) is recited in a claim, if the ingredient isnot recited in the claim, it is not used to determine the value of theratio even though it is determined to be present in a glass covered bythe claim. The preceding discussion is applicable to the othermathematical relationships, e.g. but not limiting thereto (R2O+RO+B₂O₃).

It should be appreciated that glass fiber compositions can include otheroxides that are present as tramp materials such as BaO, ZrO₂, SrO andCr₂O₃, which are usually present in amounts of up to 0.1 wt %.

Further, it should be appreciated that the glass compositions disclosedherein can also include small amounts of other materials, for examplemelting and refining aids, tramp materials or impurities. For exampleand without limiting the present invention, melting and fining aids,such as FeO, Fe₂O₃ and SO₃, are useful during production of the glass,but their residual amounts in the glass can vary and typically haveminimal, if any, material effect on the properties of the glass product.In addition, small amounts of the additives discussed above can enterthe glass composition as tramp materials or impurities included in theraw materials of the main constituents, e.g. 0 to 0.5 wt % for SO₃, FeOand Fe₂O₃.

Shown in Table 1 are several examples of glass compositions of anembodiment of the invention, which relates to the use of clay havinghigh K₂O and low TiO₂ levels in glass batch materials and to glasscompositions having high levels K₂0 and low levels of TiO₂. K₂O and TiO₂can be added to the batch materials but are not economically removedfrom the clays used as batch material. As can be appreciated by thoseskilled in the art of glass melting and as discussed above, high K₂Olevels, e.g. up to 0.70 wt % in the glass raises the forming temperatureby as much as about 7 to 10° C. in relation to a glass made from claythat introduces 0.10 wt % K₂O. One embodiment of the present inventionrelates to an improved E-type glass having low weight percent B₂O₃, aforming temperature no greater than 1230° C., preferably no greater than1222° C. and a delta T of at least 50° C. and preferably up to 65° C.The following are the main constituents in wt % based on the totalweight percent of the final glass composition. The K₂O and TiO₂ listedin the ranges below for commercial glasses may or may not be added tothe batch as separate ingredient. If the K₂O and TiO₂ are not added, itis expected that they would be present in the clay in varying wt %depending on the geographical location of the clay. Although the K₂O andTiO₂ would be present in the clay, the invention contemplates separateadditions of K₂O and/or TiO₂ to be within the ranges listed below.

In those instances when the clay has high wt % of K₂O, e.g. 0.60 wt %,it is necessary to counteract the effect of the K₂O. More particularly,the K₂O increases the forming temperature; therefore, the ingredients inthe batch materials have to be modified so as to maintain a low formingtemperature, e.g. below 1240° C. In one embodiment of the invention sucha glass is as follows.

most preferred broad range preferred range range SiO₂ (wt %) 52 to 60 54to 59 55 to 58 Al₂O₃ (wt %) 8 to 16 11 to 14 12 to 14 CaO (wt %) 21 to26 22 to 25 23 to 25 MgO (wt %) 1 to 5 1 to 4 2 to 3 K₂O (wt %) up to1.00 0.30 to 1.00 0.30 to 0.80 Na₂O (wt %) up to 1.00 0.30 to 1.00 0.30to 0.90 K₂O + Na₂O (wt %) 0.70 to 2.00 0.80 to 1.5 0.90 to 1.20 B₂O₃ (wt%) 1.00 to 3.50 1.10 to 2.00 1.20 to 1.50 Fe₂O₃ (wt %) 0.10 to 0.50 0.15to 0.45 0.20 to 0.40 TiO₂ up to 2.0 Up to 1.5 Up to 1.3

The range provided for B₂O₃ is not limiting to the invention, and it isrecommended the level of boron be adjusted to meet local environmentalregulations. As such, the invention may be practiced having levels ofB₂O₃ up to 3.5 wt %.

The glasses of the invention are further defined by one or more of thefollowing relationships:

broad range preferred range wt % of CaO and 26 to 28 wt % 26 to 27.70 wt% MgO (“RO”) SiO₂/CaO 2.10 to 2.80 2.20 to 2.70 SiO₂/RO 1.90 to 2.551.90 to 2.40 SiO₂/Al₂O₃ 3.70 to 5.00 3.7 to 4.90 Al₂O₃/CaO 0.45 to 0.650.50 to 0.60 SiO₂ + Al₂O₃ 66 to 73.70 wt % 66 to 72.10 wt % SiO₂ − RO26.56 to 36.60 wt % 26.50 to 34 wt % Al₂O₃/RO 0.40 to 0.60 0.46 to 0.56R2O + RO + B₂O₃ 28.00 to 32.00 wt % 28.00 to 31.00 wt % (SiO₂ + Al₂O₃)/2.00 to 3.00 2.00 to 2.70 (R2O + RO + B₂O₃) where R2O is equal to thesum of Na₂O + K₂O.

Table 1 contains experimental samples A–E and illustrative samples F andG of glass compositions incorporating features of the invention. Theranges for the glass compositions listed on Table 1 are the minimum andmaximum values for the glass compositions recited on Table 1, and forexamples A–E, and F and G. More particularly, Table 1 provides thefollowing glass compositions. A glass composition having the followingingredients:

SiO₂ 55.00 to 58 percent by weight; Al₂O₃ 12.00 to 14.00 percent byweight; CaO 23.80 to 24.80 percent by weight; MgO 2.50 to 3.00 percentby weight; TiO₂ up to 0.60 percent by weight; Na₂O 0.40 to 0.50 percentby weight; K₂O 0.40 to 0.60 percent by weight; Na₂O₂ + K₂O 0.85 to 1.50percent by weight; Fe₂O₃ 0.20 to 0.40 percent by weight; B₂O₃ 1.25 to1.55 percent by weight;

the following relationship of ingredients

RO 26.25 to 27.60 wt % SiO₂/CaO 2.20 to 2.40 SiO₂/RO 2.00 to 2.20SiO₂/Al₂O₃ 3.95 to 4.70 Al₂O₃/CaO 0.50 to 0.60 SiO₂ + Al₂O₃ 69.00 to70.50 wt % SiO₂ − RO 28.00 to 31.00 wt % Al₂O₃/RO 0.45 to 0.55 R2O +RO + B₂O₃ 28.90 to 30.00 wt % (SiO₂ + Al₂O₃)/ 2.25 to 2.45 (R2O + RO +B₂O₃)

-   -   where R2O is equal to the sum of Na2O+K2O has a log 3 forming        temperature in the range of 1210 to 1225° C. and ΔT is in the        range of 52 to 65° C.

Another glass composition defined by Examples A–E of Table 1 has thefollowing ingredients

SiO₂ 55.60 to 57.60 percent by weight; Al₂O₃ 12.35 to 13.94 percent byweight; CaO 24.40 to 24.80 percent by weight; MgO 2.55 to 2.80 percentby weight; TiO₂ 0.55 percent by weight; Na₂O 0.45 percent by weight; K₂O0.45 to 0.58 percent by weight; Na₂O + K₂O 0.90 to 1.03 percent byweight; Fe₂O₃ 0.25 to 0.38 percent by weight; B₂O₃ 1.30 to 1.50 percentby weight, and

the following relationships:

RO 26.95 to 27.56 wt % SiO₂/CaO 2.25 to 2.29 SiO₂/RO 2.02 to 2.14SiO₂/Al₂O₃ 4.00 to 4.66 Al₂O₃/CaO 0.51 to 0.56 SiO₂ + Al₂O₃ 69.18 to69.95 wt % SiO₂ − RO 28.04 to 30.65 wt % Al₂O₃/RO 0.46 to 0.51 R2O +RO + B₂O₃ 29.15 to 29.89 wt % (SiO2 + Al₂O₃)/ 2.31 to 2.40 (R2O + RO +B₂O₃)

-   -   where R2O is equal to the sum of Na₂O+K₂O. The glass composition        has a log 3 forming temperature in the range of 1156 to 1164° C.        and ΔT is in the range of 54 to 65° C.

Other glass compositions identified by Examples F and G of Table 1 havethe following ingredients

SiO₂ 56.70 to 57.85 percent by weight; Al₂O₃ 12.55 to 13.67 percent byweight; CaO 23.87 to 24.45 percent by weight; MgO 2.55 to 2.62 percentby weight; TiO₂ 0.05 to 0.34 percent by weight; Na₂O 0.44 to 0.455percent by weight; K₂O 0.45 to 0.51 percent by weight; Na₂O + K₂O 0.90to 1.03 percent by weight; Fe₂O₃ 0.30 to 0.40 percent by weight; B₂O₃1.30 to 1.50 percent by weight, and

the following relationships:

RO 26.49 to 27.00 wt % SiO₂/CaO 2.37 to 2.38 SiO₂/RO 2.10 to 2.14SiO₂/Al₂O₃ 4.15 to 4.61 Al₂O₃/CaO 0.51 to 0.57 SiO₂ + Al₂O₃ 70.37 to70.44 wt % SiO₂ − RO 30.21 to 30.85 wt % Al₂O₃/RO 0.46 to 0.52 R2O +RO + B₂O₃ 28.94 to 29.20 wt % (SiO₂ + Al₂O₃)/ 2.41 to 2.43 (R2O + RO +B₂O₃)

where R2O is equal to the sum of Na₂O+K₂O. The glasses have a log 3forming temperature in the range of 1218 to 1219° C. and ΔT is in therange of 52 to 58° C.

The experimental or laboratory examples or samples on Table 1 discussedabove and on Tables 2 to 19 to be discussed below, unless indicatedotherwise, were prepared from certified or reagent grade oxides (e.g.,pure silica or calcia). Examples F and G on Table 1 and examples H and Ion Table 2 are illustrative examples and were not prepared in thefollowing manner. The batch size for each example was 1000 grams. Theindividual batch ingredients were weighed out, combined and placed in atightly sealed glass jar or plastic container. The sealed jar orcontainer was then placed in a paint shaker for 15 minutes or in atubular mixer for 25 minutes to effectively mix the ingredients. Aportion of the batch was then placed into a platinum crucible, fillingno more than ¾ of its volume. The crucible was then placed in a furnaceand heated at 1427° C. (2600° F.) for 15 minutes. The remaining batchwas then added to the hot crucible and heated at 1427° C. (2600° F.) for15 to 30 minutes. The furnace temperature was then raised to 1482° C.(2700° F.) and held there for 2 hours. The molten glass was then frittedin water and dried. The fritted samples were reheated to a temperatureof 1482° C. (2700° F.) and held at that temperature for 2 hours. Themolten glass was then fritted again in water and dried.

The forming temperature, i.e. the glass temperature at a viscosity of1000 poise, was determined by ASTM method C965-81, and the liquidustemperature by ASTM method C829-81. The log 3 forming temperature of thecompositions reported in Tables 1–20 were determined by a comparison ofthe glass against physical standards supplied by the National Instituteof Standards and Testing (NIST). In the Tables, the majority of thereported log 3 forming temperatures is based on comparison to NIST 710A.Several of the reported log 3 forming temperatures are originally basedon NIST 717A which uses a borosilicate standard; in those instances thevalues were converted to correspond to NIST 710A. Therefore all the log3 forming temperatures are considered to based on NIST 710A.

Selected samples had ingredients added that would be found in the claysused in the batch material. Such as K₂O, TiO₂, calcium fluoride, SrOand/or Cr₂O₃.

The weight percent of the constituents of the compositions shown inTables 1–19 except for Examples F to I are based on the weight percentof each constituent in the batch. It is believed that the batch weightpercent is generally about the same as the weight percent of the meltedsample, except for glass batch materials that volatilize during melting,e.g. boron, fluorine and moisture absorbing materials. In the case ofboron, it is believed that the weight percent of B₂O₃ in a laboratorysample will be 10 to 16 weight percent less than the weight percent ofB₂O₃ in the batch composition, the precise loss depending on thecomposition and melting conditions. In the case of fluorine, it isbelieved that the weight percent of fluorine in a laboratory test samplewill be about 50 percent less than the weight percent of fluorine in thebatch composition, the precise loss depending on the composition andmelting conditions. In the case of CaO, CaO has an certified ignitionloss 3–5 wt % (an average of 4 wt %). The determination of the wt % ofthe batch materials for the samples listed on Tables 1–19 except forExamples F to I, through an oversight, did not take into account theignition loss. Therefore in practicing the invention, this fact shouldbe taken into account. Because the 4 wt % error is minimal, therecitation of the wt % of CaO recited in the claims covering theembodiments of the glass compositions listed on Tables 1–19 does nottake into account the ignition loss. Table 20 has production samples;the analysis of the ingredients of the examples on Table 20 weremeasured using XRF analysis.

As can be appreciated by those skilled in the art of converting datafrom laboratory melt sample to data used to prepare batch materials forcommercial glass production, the melting and fining conditions of thecommercial furnace to be used to melt and fine the glass has to be takeninto consideration. It is believed that glass fiber compositions madefrom commercial grade materials and melted under conventional operatingconditions will have similar batch and melt weight percents as discussedabove, with the precise loss depending, in part, on the furnaceoperating temperature, through-put and quality of commercial batchmaterials. The amount of boron and fluorine reported in the tables takesinto consideration the expected loss of these materials and representsthe expected amount of the material in the glass composition. It shouldfurther be appreciated that the glass compositions disclosed herein canalso include small amounts of other materials, for example melting andrefining aids, tramp materials or impurities. For example and withoutlimiting the present invention, melting and fining aids, such as SO₃,are useful during production of the glass, but their residual amounts inthe glass can vary and have no material effect on the properties of theglass product. In addition, small amounts of the additives discussedabove can enter the glass composition as tramp materials or impuritiesincluded in the raw materials of the main constituents.

With reference to Tables 1–20, in each column of each Table, the upperportion of the column lists the wt % of the ingredients in the glasscomposition based on the batch materials as was discussed above. Themiddle portion of the column lists the mathematical relationship of theingredients discussed above for the particular glass composition in thesame column to obtain the thermal properties listed in the bottomportion of the column e.g. forming temperature, liquidus temperature anddelta T (except for certain compositions of Table 20 which is discussedbelow). Table 20 lists production glasses. The amount of eachconstituent of the commercial compositions shown in the Table 20 is theweight percent in the glass. The weight percent for the B₂O₃ wasdetermined using Neutron Transmission analysis techniques and the weightpercent for the remaining constituents was determined using X-rayfluorescence analysis (also referred to as “XRF analysis”), all of whichare well known to those skilled in the art.

Tables 2 through 19 include, but are not limited to glass compositionsdisclosed in U.S. patent application Ser. No. 09/980,248, filed Nov. 28,2001, in the name of Frederick T. Wallenberger for “Glass FiberCompositions” (hereinafter “U.S. patent application Ser. No.09/980,248”); in PCT International Application No. PCT/US01/27451, filedSep. 5, 2001, in the name of Frederick T. Wallenberger for “Glass FiberForming Compositions” (hereinafter “USPCT No. 01/27451”); and inInternational Application No. PCT/US00/14155. U.S. patent applicationSer. No. 09/980,248 and International Application No. PCT/US00/14155 arejointly referred to as “U.S. patent application Ser. No. 09/980,248Combined”.

U.S. patent application Ser. No. 09/980,248 Combined and USPCT No.01/27451 discloses base composition for the low boron glass fibers thatare suitable for textiles and glass fiber reinforcements, that may beused in the practice of the present invention. In general, the basecompositions of U.S. patent application Ser. No. 09/980,248 Combined andUSPCT No. 01/27451 include the following main constituents in weightpercent ranges based on the total weight of the final glass compositionwith the exception that USPCT No. 01/27451 glass compositions are boronfree.

broad range preferred range most preferred range SiO₂ (wt %) 52 to 62 52to 61 53 to 59 Na₂O (wt %) 0 to 2 up to 1.5 up to 1 CaO (wt %) 16 to 2520 to 25 22 to 24 Al₂O₃ (wt %) 8 to 16 11 to 14 12 to 14 Fe₂O₃ (wt %)0.05 to 0.80 up to 0.5 up to 0.4 K₂O (wt %) 0 to 2 Up to 1 up to 0.1B₂O₃ (wt %) 1 to 5 1 to 3.5 1 to 2.5

In one embodiment the glass comparison of U.S. patent application Ser.No. 09/980,248 Combined, the glass composition can include on or more ofthe following materials in the following amounts.

broad range preferred range Li₂O (wt %) 0.05 to 1.5 0.2 to 1 ZnO (wt %)0.05 to 1.5 0.2 to 1 MnO (wt %) 0.05 to 3 up to 1 MnO₂ (wt %) 0.05 to 3up to 1For a complete discussion of the glass compositions disclosed in U.S.patent application Ser. No. 09/980,248 Combined, and disclosed in USPCTNo. 01/27451, reference should be made thereto.

As discussed above the examples of Table 1 incorporate features of oneembodiment of the invention, a low boron glass composition (see theupper portion of the columns on Table 1) having a forming temperaturebelow 1240° C., more preferably below 1225° C. and a delta T of greaterthan 50° C. (see the lower portion of the columns on Table 1). Theexamples of Tables 1–20 include another feature of the invention,mathematical relationship of the ingredients in the glass composition(see middle portion of the columns on Tables 1–20) to provide a formingtemperature below 1240° C. and a delta T of greater than 50° C. (see thelower portion of the columns on Tables 1–20). The mathematicalrelationship of the ingredients of the glass compositions on Table 1were discussed above. Tables 2–19 include, but are not limited toexamples of glass compositions disclosed in U.S. patent application Ser.No. 09/980,248 Combined and/or in USPCT No. 01/27451. Additionalexamples within the scope of the inventions of U.S. patent applicationSer. No. 09/980,248 Combined and/or in USPCT No. 01/27451 are includedherein. For example, but not a complete relationship, examples 188–236are selected from U.S. patent application Ser. No. 09/980,248 Combinedand examples 7–24, 43–50,78–185, and 219–267 are selected from USPCT No.01/27451. Examples A–E, 25, 30–32, 60–75 are examples, among others,presented by this application. The examples identified as selected fromU.S. patent application Ser. No. 09/980,248 Combined and/or in USPCT No.01/27451 and those added to the Tables by the instant disclosure are notcomplete. For a complete comparison reference may be had to U.S. patentapplication Ser. No. 09/980,248 Combined and/or in USPCT No. 01/27451.

For a better appreciation of the invention the samples on Tables 2–19are categorized according to the following types of glass compositions.

-   Type-1 Glasses boron-free (Table 2)-   Type-2 Glasses up to about 5.10 wt % B₂O₃ (Tables 3–11)-   Type-3 Glasses boron-free with lithium oxide (Tables 12 and 13)-   Type-4 Glasses boron-free with lithium and zinc oxide (Tables 14 and    15)-   Type-5 Glasses boron-free with zinc oxide (Table 16)-   Type-6 Glasses up to 5 wt % B₂O₃ with lithium oxide (Tables 17 and    18)-   Type-7 Glasses miscellaneous glass (Table 19)    Table 20, as previously discussed includes production glasses.

Table 2 (Type 1 Glasses) includes glass compositions of a quaternarysystem that includes SiO₂ in the range of 57–60 wt %, preferably in therange of 57.25–59.50 wt % and more preferable in the range of57.40–59.10; Al₂O₃ in the range of 12–14 wt %, preferably in the rangeof 12–13.50 wt % and more preferably in the range of 12.15–13.45 wt %;CaO in the range of 23–25 wt %, preferable in the range of 23.50–24.50wt % and more preferable in the range of 23.70–24.20 wt %, and MgO inthe range of 2–3 wt %, preferably in the range of 2.25–2.75 wt % andmore preferably in the range of 2.50–2.60 wt %. The glass compositionsof Table 2 further include TiO₂ in the range of up to 1.25 wt %,preferably in the range of 0.25–1.20 wt % and more preferably in therange of 0.50–1.15 wt %; Na₂O in the range of 0.75–1.25, preferably inthe range of 0.75–1.00 wt % and more preferably in the range of0.85–0.95 wt %; and Fe₂O₃ in the range of up to 0.50 wt %, preferably0.10–0.50 wt % and more preferably in the range of 0.30–0.40 wt %. Thecompositions of Table 2 are boron free. Compositions 1–6 of Table 2further include TiO₂ in the range of 1.00–1.25 wt %, preferably in therange of 1.00–1.20 wt % and more preferably in the range of 1.05–1.15 wt%; Na₂O in the range of 0.75–1.25, preferably in the range of 0.75–1.00wt % and more preferably in the range of 0.85–0.95 wt %; and Fe₂O₃ inthe range of up to 0.35 wt %, preferably 0.10–0.30 wt % and morepreferably in the range of 0.20–0.30 wt %. Compositions H and I includeTiO₂ in the range of 0–0.9 wt %, preferably in the range of 0.25–0.75 wt% and more preferably in the range of 0,50–0.6 wt %; Na₂O in the rangeof 0.75–1.25, preferably in the range of 0.75–1.00 wt % and morepreferably in the range of 0.85–0.95 wt %; and Fe₂O₃ in the range of upto 0.50 wt %, preferably 0.10–0.40 wt % and more preferably in the rangeof 0.30–0.40 wt %.

A glass composition having the ingredients of Table 2 within the aboveranges and at least one of the following relationships provides a glasscomposition having a forming temperature below 1240° C. and a delta T ofgreater than 50° C., e.g.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 26 to 28 wt %26.00 to 27.25 wt % SiO₂/CaO 2.10 to 2.80 2.30 to 2.80 SiO₂/RO 1.90 to2.55 1.90 to 2.40 SiO₂/Al₂O₃ 3.70 to 5.00; 4.20 to 5.00 Al₂O₃/CaO 0.40to 0.75 0.50 to 0.60 SiO₂ + Al₂O₃ 66 to 73.7 wt % 70.80 to 73.7 wt %R₂O + RO 27 to 28.15 wt 27.15 to 20 wt % (SiO₂ + Al₂O₃)/ 2.0 to 3.0 2.30to 3.00 (R₂O + RO) SiO₂ − RO 26.5 to 36.6 wt % 30.50 to 36.60 wt %Al₂O₃/RO 0.4 to 0.6 0.46 to 0.56

The Type 1 glass compositions are not expected to have any Li₂O or K₂O,therefore R2O is equal to the wt % of Na₂O.

As can be appreciated, Table 2 also provides ranges for the ingredientsand the relationships. For example, but not limiting to the invention,the ranges for the ingredients of the glass compositions listed on Table2 are as follows:

SiO₂ 57.45 to 59.05 percent by weight; Al₂O₃ 12.20 to 13.40 percent byweight; CaO 23.75 to 24.35 percent by weight; MgO 2.55 percent byweight; TiO₂ 1.10 percent by weight; Na₂O₃ 0.90 percent by weight, andFe₂O₃ 0.25 percent by weight.

The range of the mathematical relationships of the ingredients fromTable 2 for the glass compositions listed on Table 2 is found in Table21 in the column entitled “Type 1 Glasses”. The glasses on Table 2 havea log 3 forming temperature in the range of 1232 to 1240° C. and a ΔT inthe range of 58 to 74° C.

Table 2 also provides ranges for the Examples 1–6. More particularly,from Table 2 Example 1–6 glass compositions have the followingingredients and ranges:

SiO₂ 57.45 to 59.05 percent by weight; Al₂O₃ 12.20 to 13.68 percent byweight; CaO 23.75 to 24.50 percent by weight; MgO 2.55 to 2.58 percentby weight; TiO₂ 0.55 to 1.10 percent by weight; Na₂O₃ 0.90 to 0.91percent by weight, and Fe₂O₃ 0.25 to 0.35 percent by weight.

The range of the mathematical relationship of the ingredients from Table2 for the glass compositions of Examples 1–6 can be found on Table 21under Type 1 Glasses. The glass compositions of Examples 1–6 have a log3 forming temperature in the range of 1232 to 1240° C. and a ΔT in therange of 58 to 74° C.

Further, Table 2 provides ranges for the Examples H and I. Moreparticularly, from Table 2 Examples H and I glass compositions have thefollowing ingredients and ranges:

SiO₂ 57.60 to 58.18 percent by weight; Al₂O₃ 13.55 to 13.68 percent byweight; CaO 23.75 to 24.50 percent by weight; MgO 2.55 to 2.58 percentby weight; TiO₂ 0.55 percent by weight; Na₂O₃ 0.90 to 0.91 percent byweight, and Fe₂O₃ 0.35 percent by weight.the ranges for the mathematical relationships of the ingredients fromTable 2 are as follows:

RO 26.33 to 27.05 wt % SiO₂/CaO 2.35 to 2.45 SiO₂/RO 2.13 to 2.20SiO₂/Al₂O₃ 4.25 Al₂O₃/CaO 0.55 to 0.58 SiO₂ + Al₂O₃ 71.15 to 71.86 wt %SiO₂ − RO 30.55 to 31.85 wt % Al₂O₃/RO 0.50 to 0.52 R2O + RO 27.24 to27.95 wt % (SiO₂ + Al₂O₃)/ 2.55 to 2.64 (R2O + RO)

The glass compositions of Examples H and I have a log 3 formingtemperature in the range of 1238 to 1240° C. and a ΔT of 55° C.

Tables 3–11 (Type 2 Glasses) include glass compositions of a quaternarysystem that includes SiO₂ in the range of 50–60 wt %, preferably in therange of 52.25–59.00 wt % and more preferable in the range of52.90–58.00 wt %; Al₂O₃ in the range of 10–14 wt %, preferably in therange of 11–14 wt % and more preferably in the range of 12–14 wt %; CaOin the range of 21–26 wt %, preferable in the range of 21.50–25.50 wt %and more preferable in the range of 22–25 wt %, and MgO in the range of1–4 wt %, preferably in the range of 1.25–3.50 wt % and more preferablyin the range of 1.45–3.25 wt %. The compositions of Tables 3–11 includeB₂O₃ in an amount within the range of greater than 0 to 5.10 wt %, e.g.0.90–5.10 wt %. The compositions of Table 3–11 further contemplate TiO₂in the range of 0.25–1.25 wt %, more likely in the range of 0.40–1.20 wt% and most likely in the range of 0.45–1.15 wt %; Na₂O in the range of0.25–1.25, preferably in the range of 0.35–1.00 wt % and more preferablyin the range of 0.40–0.95 wt %; K₂O expected in amounts up to 0.60 wt %;and Fe₂O₃ in the range of up to 0.50 wt %, preferably up to −0.45 wt %and more preferably up to 0.40 wt %. Other ingredients included in theglass compositions of Tables 3–11 but not limited thereto are fluorinein amounts up to 0.50 wt %; SrO in amounts up to 0.15 wt % and Cr₂O₃ inamounts up to 0.15 wt %.

A glass composition having ingredients of Tables 3–11 within the aboveranges and at least one of the following relationships provides a glasscomposition having a forming temperature below 1240° C. and a delta T ofgreater than 50° C.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 24 to 29 wt %24.75 to 27.60 wt % SiO₂/CaO 2.10 to 2.80 2.15 to 2.75 SiO₂/RO 1.95 to2.55 1.90 to 2.40 SiO₂/Al₂O₃ 3.70 to 5.00 3.70 to 4.90 Al₂O₃/CaO 0.45 to0.65 0.45 to 0.65 SiO₂ + Al₂O₃ 66 to 73.7 wt % 66 to 72.1 wt % R₂O +RO + B₂O₃ 27.5 to 34 wt % 28 to 33 wt % (SiO₂ + Al₂O₃)/ 2.00 to 3.002.00 to 2.70 (R₂O + RO + B₂O₃) SiO₂ − RO 26.5 to 36.6 wt % 26.5 to 34 wt% Al₂O₃/RO 0.40 to 0.60 0.46 to 0.56

Type 2 glasses of Tables 3–11 do not consider Li₂O as an ingredient;therefore for Tables 3–11, R2O is equal to the sum of the wt % of K₂Oand Na₂O. If one of the ingredients is not present in the glass it isgiven a 0 wt %. For the glasses listed on each of the Tables 3, 4, 6, 7,10 and 11, only the addition of Na₂O is considered; therefore for theglasses on the individual Tables 3, 4, 6, 7, 10 and 11, R2O is equal tothe wt % of Na₂O. For the glasses listed on the individual Tables 5, 8and 9, Na₂O and K₂O are considered; therefore for the glasses on theindividual Tables 5, 8 and 9, R2O is equal to the sum of the wt % ofNa₂O and K₂O.

As can be appreciated, each of the Tables 3–11 provides ranges for theingredients and the relationships. For example and not limiting to theinvention, Tables 3–11 provide glass compositions having the followingingredients in the following ranges:

SiO₂ 53.00 to 57.75 percent by weight; Al₂O₃ 12.20 to 14 percent byweight; CaO 22.25 to 24.95 percent by weight; MgO 1.50 to 3.00 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Na₂O 0.45 to 0.90percent by weight; K₂O 0 to 0.38 percent by weight; Fe₂O₃ 0 to 0.30percent by weight; B₂O₃ 1.30 to 5.02 percent by weight; F 0 to 0.50percent by weight; SrO 0 to 0.13 percent by weight, and Cr₂O₃ 0 to 0.13percent by weight.

The mathematical relationship of the ingredients is found on Table 21 inthe column entitled “Type 2 Glasses”.

Table 3 provides glass compositions having ingredients in the followingranges:

SiO₂ 56.00 to 56.65 percent by weight; Al₂O₃ 13.05 to 13.60 percent byweight; CaO 23.50 to 24.25 percent by weight; MgO 2.50 to 2.55 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Na₂O 0.90 percent byweight; Fe₂O₃ 0.25 percent by weight, and B₂O₃ 2.00 percent by weight.

The ranges for the mathematical relationships of ingredients of theglass compositions on Table 3 from Table 3 are as follows:

RO 26.05 to 26.75 wt % SiO₂/CaO 2.31 to 2.41 SiO₂/RO 2.09 to 2.17SiO₂/Al₂O₃ 4.12 to 4.28 Al₂O₃/CaO 0.56 to 0.57 SiO₂ + Al₂O₃ 69.60 to69.95 wt % SiO₂ − RO 29.25 to 30.60 wt % Al₂O₃/RO 0.50 to 0.52 R2O +RO + B₂O₃ 28.95 to 29.65 wt % (SiO₂ + Al₂O₃)/ 2.35 to 2.41 (R2O + RO +B₂O₃)

The glass compositions of Table 3 have a log 3 forming temperature inthe range of 1200 to 1220° C. and a ΔT is in the range of 56 to 69° C.

Table 4 provides glass compositions having Ingredients in the followingranges:

SiO₂ is 56.25 to 57.75 percent by weight; Al₂O₃ is 12.20 to 13.20percent by weight; CaO 23.75 to 24.25 percent by weight; MgO 2.55percent by weight; TiO₂ 1.10 percent by weight; Na₂O 0.90 percent byweight; Fe₂O₃ 0.25 percent by weight, and B₂O₃ 1.30 to 1.40 percent byweight.

The ranges for the mathematical relationships of the ingredients for theglass compositions of Table 4 from Table 4 are as follows:

RO 26.30 to 26.80 wt % SiO₂/CaO 2.32 to 2.43 SiO₂/RO 2.10 to 2.20SiO₂/Al₂O₃ 4.26 to 4.73 Al₂O₃/CaO 0.51 to 0.56 SiO₂ + Al₂O₃ 69.45 to69.95 wt % SiO₂ − RO 29.45 to 31.45 wt % Al₂O₃/RO 0.46 to 0.50 R2O +RO + B₂O₃ 28.50 to 29.00 wt % (SiO₂ + Al₂O₃)/ 2.39 to 2.45. (R2O + RO +B₂O₃)

The glass compositions of Table 4 have a log 3 forming temperature inthe range of 1200 to 1218° C. and a ΔT in the range of 55° C. to 70° C.

The glass compositions of Table 5 have the following ingredients in thefollowing ranges:

SiO₂ 55.19 to 56.00 percent by weight; Al₂O₃ 13.10 to 13.80 percent byweight; CaO 24.50 to 24.67 percent by weight; MgO 2.55 to 2.95 percentby weight; TiO₂ 1.10 percent by weight; Na₂O 0.45 percent by weight; K₂O0.45 to 0.58 percent by weight; Fe₂O₃ 0.25 to 0.38 percent by weight,and B₂O₃ 1.30 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 5 from Table 5 are as follows:

RO 27.08 to 27.45 wt % SiO₂/CaO 2.25 to 2.28 SiO₂/RO 2.01 to 2.07SiO₂/Al₂O₃ 4.01 to 4.19 Al₂O₃/CaO 0.53 to 0.56 SiO₂ + Al₂O₃ 68.75 to69.37 wt % SiO₂ − RO 27.78 to 28.92 wt % Al₂O₃/RO 0.48 to 0.51 R2O +RO + B₂O₃ 29.28 to 29.74 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.31 to2.37

The glass compositions of Table 5 have a log 3 forming temperature inthe range of 1210 to 1222° C. and a ΔT in the range of 53 to 79° C.

Table 6 provides glass compositions having ingredients in the followingranges:

SiO₂ 56.15 to 57.60 percent by weight; Al₂O₃ 13.25 to 13.95 percent byweight; CaO 24.40 to 24.95 percent by weight; MgO 2.55 percent byweight; TiO₂ 0.55 percent by weight; Na₂O 0.90 percent by weight; Fe₂O₃0.25 to 0.35 percent by weight, and B₂O₃ 1.30 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 6 from Table 6 are as follows:

RO 26.95 to 27.50 wt % SiO₂/CaO 2.25 to 2.36 SiO₂/RO 2.04 to 2.14SiO₂/Al₂O₃ 4.01 to 4.66 Al₂O₃/CaO 0.54 to 0.57 SiO₂ + Al₂O₃ 69.50 to69.99 wt % SiO₂ − RO 28.65 to 30.65 wt % Al₂O₃/RO 0.46 to 0.51 R2O +RO + B₂O₃ 29.15 to 29.70 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.34 to2.40.

The glass compositions of Table 6 have a log 3 forming temperature inthe range of 1211 to 1220° C. and a ΔT is in the range of 52 to 66° C.

Table 7 provides glass compositions having ingredients in the followingranges:

SiO₂ 55.25 to 56.15 percent by weight; Al₂O₃ 13.05 to 13.30 percent byweight; CaO 23.00 to 24.20 percent by weight; MgO 2.55 percent byweight; TiO₂ 0.25 to 1.25 percent by weight; Na₂O 0.90 percent byweight; Fe₂O₃ 0.25 percent by weight; and B₂O₃ 3.00 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 7 from Table 7 are as follows:

RO 25.55 to 26.75 wt % SiO₂/CaO 2.28 to 2.44 SiO₂/RO 2.07 to 2.20SiO₂/Al₂O₃ 4.15 to 4.30 Al₂O₃/CaO 0.55 to 0.56 SiO₂ + Al₂O₃ 68.20 to69.20 wt % SiO₂ − RO 28.45 to 30.60 wt % Al₂O₃/RO 0.50 to 0.51 R2O +RO + B₂O₃ 29.45 to 30.65 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.24 to2.35

The glass compositions of Table 7 have a log 3 forming temperature inthe range of 1193 to 1212° C. and a ΔT is in the range of 64 to 90° C.

Table 8 provides glass compositions having ingredients in the followingranges:

SiO₂ 54.12 to 55.25 percent by weight; Al₂O₃ 13.20 to 13.40 percent byweight; CaO 24.20 to 24.55 percent by weight; MgO 2.55 percent byweight; TiO₂ 0.55 percent by weight; Na₂O 0.45 to 0.50 percent byweight; K₂O 0.45 to 0.55 percent by weight; Fe₂O₃ 0.25 to 0.28 percentby weight; B₂O₃ 3.00 percent by weight; F up to 0.20 percent by weight,and SrO up to 0.12 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 8 from Table 8 are as follows:

RO 26.75 to 27.55 wt % SiO₂/CaO 2.20 to 2.28 SiO₂/RO 1.96 to 2.07SiO₂/Al₂O₃ 4.06 to 4.15 Al₂O₃/CaO 0.54 to 0.55 SiO₂ + Al₂O₃ 67.55 to68.55 wt % SiO₂ − RO 26.57 to 28.30 wt % Al₂O₃/RO 0.49 to 0.50 R2O +RO + B₂O₃ 30.65 to 31.40 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.14 to2.22

The glass compositions of Table 8 have a log 3 forming temperature inthe range of 1190 to 1204° C. and a ΔT is in the range of 55 to 83° C.

Table 9 provides glass compositions having Ingredients in the followingranges:

SiO₂ 53.00 to 53.50 percent by weight; Al₂O₃ 13.10 to 14.00 percent byweight; CaO 24.00 percent by weight; MgO 1.25 to 2.50 percent by weight;TiO₂ 0.50 percent by weight; Na₂O 0.90 percent by weight; K₂O 0.37percent by weight; Fe₂O₃ 0.10 percent by weight; B₂O₃ 4.93 to 5.02percent by weight; F 0.50 percent by weight; SrO 0.13 percent by weight,and Cr₂O₃ 0.13 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 9 from Table 9 are as follows:

RO 25.50 to 26.50 wt % SiO₂/CaO 2.21 to 2.23 SiO₂/RO 2.00 to 2.10SiO₂/Al₂O₃ 3.82 to 4.05 Al₂O₃/CaO 0.55 to 0.58 SiO₂ + Al₂O₃ 66.10 to67.50 wt % SiO₂ − RO 26.50 to 28.00 wt % Al₂O₃/RO 0.49 to 0.55 R2O +RO + B₂O₃ 31.70 to 32.79 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.02 to2.13

The glass compositions of Table 9 have a log 3 forming temperature inthe range of 1167 to 1177 and a ΔT is in the range of 57 to 69° C.

Table 10 provides glass compositions having ingredients in the followingranges:

SiO₂ 55.40 to 57.75 percent by weight; Al₂O₃ 12.20 to 13.80 percent byweight; CaO 22.25 to 24.85 percent by weight; MgO 2.05 to 2.60 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Na₂O 0.90 percent byweight; Fe₂O₃ 0.25 percent by weight, and B₂O₃ 1.00 to 3.00 percent byweight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 10 from Table 10 are as follows:

RO 26.80 to 27.35 wt % SiO₂/CaO 2.23 to 2.55 SiO₂/RO 2.05 to 2.27SiO₂/Al₂O₃ 4.04 to 4.69 Al₂O₃/CaO 0.51 to 0.59 SiO₂ + Al₂O₃ 69.00 to70.95 wt % SiO₂ − RO 28.05 to 32.55 wt % Al₂O₃/RO 0.46 to 0.53 R2O +RO + B₂O₃ 28.15 to 30.25 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.28 to2.67

The glass compositions of Table 10 have a log 3 forming temperature inthe range of 1202 to 1240° C. and a ΔT is in the range of 53 to 100° C.

The glass compositions listed on Table 10 and the glasses within thescope of the embodiment of Table 10 have a forming temperature in therange of 1202 to 1240° C. It should be noted that the measured delta Tfor Example 91 was 34° C.; it is believed that this is a measuring errorthe liquidus temperature because the glass composition of Example 90 hassimilar ingredients, a lower liquidus temperature and a delta T of 100°C. Therefore the delta T of Example 91 is considered to be about 90° C.The preferred glass compositions from Table 10 are those that providethe forming temperature range 1202 to 1219° C. and a delta T greaterthan 5° C., more particularly Examples 78–91.

The glass compositions of Examples 78–91 of Table 10 from Table 10 havethe following ingredients in the following ranges:

SiO₂ 55.40 to 56.65 percent by weight; Al₂O₃ 13.05 to 13.80 percent byweight; CaO 23.00 to 24.85 percent by weight; MgO 2.50 to 2.55 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Na₂O 0.90 percent byweight; Fe₂O₃ 0.25 percent by weight, and B₂O₃ 2.00 to 3.00 percent byweight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Examples 78–91 of Table 10 from Table are asfollows:

RO 25.55 to 27.35 wt % SiO₂/CaO 2.23 to 2.44 SiO₂/RO 2.03 to 2.20SiO₂/Al₂O₃ 4.06 to 4.34 Al₂O₃/CaO 0.54 to 0.57 SiO₂ + Al₂O₃ 68.95 to69.95 wt % SiO₂ − RO 28.05 to 30.60 wt % Al₂O₃/RO 0.49 to 0.53 R2O +RO + B₂O₃ 28.95 to 30.25 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.28 to2.41

The glass composition of Examples 78–91 have a log 3 forming temperaturein the range of 1202 to 1219° C. and a ΔT is in the range of 53 to 100°C.

The glass compositions of Table 11 from Table 11 have the followingingredients in the following ranges:

SiO₂ 56.10 to 57.75 percent by weight; Al₂O₃ 12.20 to 13.38 percent byweight; CaO 23.75 to 24.42 percent by weight; MgO 2.55 percent byweight; TiO₂ 0.55 to 1.10 percent by weight; Na₂O 0.90 percent byweight; Fe₂O₃ 0.25 percent by weight; and B₂O₃ 1.30 to 1.40 percent byweight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 11 from Table 11 are as follows:

RO 26.30 to 26.97 wt % SiO₂/CaO 2.30 to 2.43 SiO₂/RO 2.08 to 2.20SiO₂/Al₂O₃ 4.19 to 4.73 Al₂O₃/CaO 0.51 to 0.54 SiO₂ + Al₂O₃ 69.48 to69.95 wt % SiO₂ − RO 29.13 to 31.45 wt % Al₂O₃/RO 0.46 to 0.50 R2O +RO + B₂O₃ 28.60 to 29.17 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.38 to2.44

The glass compositions of Table 11 have a log 3 forming temperature inthe range of 1215 to 1218° C. and a ΔT in the range of 63° C. to 65° C.

Tables 12 and 13 (Type 3 Glasses) include glass compositions of aquaternary system that includes SiO₂ in the range of 55–62 wt %,preferably in the range of 56–61 wt % and more preferably in the rangeof 57.5–61 wt %; Al₂O₃ in the range of 10–14 wt %, preferably in therange of 11–14 wt % and more preferably in the range of 11.75–13.75 wt%; CaO in the range of 20–26 wt %, preferable in the range of21.50–25.00 wt % and more preferable in the range of 21.75–24.50 wt %,and MgO in the range of 1–4 wt %, preferably in the range of 1.35–3.50wt % and more preferably in the range of 1.60–3.25 wt %. Thecompositions of Tables 12 and 13 are boron free. The compositions ofTables 12 and 13 contemplate a TiO₂ in the range of 0.25–1.75 wt %, morelikely in the range of 0.40–1.60 wt % and most likely more preferably inthe range of 0.45–1.55 wt %; Na₂O in amounts up to 0.75 wt %, preferablyin amounts up to 0.70 wt % and more preferably in amounts up to 0.65 wt%; Li₂O in amounts in the range of 0.10 to 1.25 wt %, preferably in therange of 0.20 to 1.10 wt %, and more preferably in the range of 0.30 to1.00 wt %, and Fe₂O₃ in the range of up to 0.50 wt %, preferably up to0.45 wt % and more preferably up to 0.30 wt %.

A glass composition having ingredients of Tables 12 and 13 within theabove ranges and at least one of the following relationships provides aglass composition having a forming temperature below 1240° C. and adelta T of greater than 50° C.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 23.50 to 27.50wt % 23.75 to 27.00 wt % SiO₂/CaO 2.10 to 2.80 2.30 to 2.80 SiO₂/RO 1.90to 2.55 2.10 to 2.55 SiO₂/Al₂O₃ 3.70 to 5.00 4.20 to 5.00 Al₂O₃/CaO 0.45to 0.65 0.45 to 0.60 SiO₂ + Al₂O₃ 66 to 73.7 wt % 70.8 to 73.7 wt %R₂O + RO 24.75 to 28 wt % 25 to 27.75 wt % (SiO₂ + Al₂O₃)/(R₂O + RO)2.00 to 3.00 2.30 to 3.00 SiO₂ − RO 26.5 to 36.6 wt % 30.50 to 36.6 wt %Al₂O₃/RO 0.40 to 0.60 0.46 to 0.53

The Type 3 Glasses do not consider the addition of K2O; therefore forType 3 Glasses R2O is equal to the sum of the wt % of Na₂O and Li₂O.

As can be appreciated, each of the Tables 12 and 13 provides ranges forthe ingredients and the relationships. More particularly, the glasscompositions of Tables 12 and 13 from Tables 12 and 13 have thefollowing ingredients in the following ranges:

SiO₂ 57.65 to 60.75 percent by weight; Al₂O₃ 12.00 to 13.64 percent byweight; CaO 22 to 24.155 percent by weight; MgO 1.70 to 3.40 percent byweight; TiO₂ 0.50 to 1.50 percent by weight; Na₂O 0.30 to 0.60 percentby weight; Li₂O 0.30 to 1.00 percent by weight, and Fe₂O₃ up to 0.25percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Tables 12 and 13 from Tables 12 and 13 are onTable 21 under the column entitled “Type 3 Glasses”. The glasscompositions of Tables 12 and 13 have a log 3 forming temperature in therange of 1205 to 1240° C., and a ΔT in the range of 50 to 100° C.

The glass compositions of Table 12 from Table 12 have the followingingredients in the following ranges:

SiO₂ 58.25 to 59.97 percent by weight; Al₂O₃ 12.19 to 13.64 percent byweight; CaO 22.04 to 23.65 percent by weight; MgO 2.50 to 3.12 percentby weight; TiO₂ 0.50 to 1.50 percent by weight; Na₂O up to 0.30 percentby weight; Li₂O 0.90 to 0.91 percent by weight, and Fe₂O₃ 0.20 to 0.25percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 12 are as follows:

RO 24.94 to 26.20 wt % SiO₂/CaO 2.47 to 2.72 SiO₂/RO 2.23 to 2.40SiO₂/Al₂O₃ 4.31 to 4.92 Al₂O₃/CaO 0.55 to 0.59 SiO₂ + Al₂O₃ 71.55 to73.03 wt % SiO₂ − RO 32.15 to 34.91 wt % Al₂O₃/RO 0.48 to 0.52 R2O + RO25.84 to 27.10 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.64 to 2.79

The glass compositions of Table 12 have a log 3 forming temperature inthe range of 1211° C. and to 1218° C., and a ΔT in the range of 56 to68° C.

The glass compositions of Table 13 from Table 13 have the followingingredients in the following ranges:

SiO₂ 57.65 to 60.75 percent by weight; Al₂O₃ 12.00 to 13.40 percent byweight; CaO 22.00 to 24.15 percent by weight; MgO 1.70 to 3.12 percentby weight; TiO₂ 0.50 to 1.50 percent by weight; Na₂O 0.45 to 0.90percent by weight; Li₂O 0.45 to 1.00 percent by weight, and Fe₂O₃ up to0.25 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 13 from Table 13 is as follows:

RO 24.25 to 26.70 wt % SiO₂/CaO 2.39 to 2.72 SiO₂/RO 2.16 to 2.51SiO₂/Al₂O₃ 4.30 to 4.92 Al₂O₃/CaO 0.50 to 0.59 SiO₂ + Al₂O₃ 71.05 to73.67 wt % SiO₂ − RO 31.35 to 36.56 wt % Al₂O₃/RO 0.47 to 0.55 R2O + RO24.91 to 27.90 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.30 to 2.96

The glass compositions have a log 3 forming temperature in the range of1205 to 1240° C. and a ΔT are in the range of 50 to 101° C.

The glass compositions listed on Table 13 and the glasses within thescope of the embodiment of Table 13 have a forming temperature in therange of 1205 to 1240° C. and a delta T in the range of 50–100° C.;however the preferred glass compositions from Table 13 are those thatprovide the forming temperature range of 1205 to 1220° C. and morepreferably in the range of 1205–1218° C. more particularly Examples 123,124, 125, 127–132, 147, 153, 155, 157, 160 and 161 with the appropriatedelta T, e.g. 50° C. or greater.

The glass compositions of Examples 123, 124, 125, 127–132, 147, 153,155, 157, 160 and 161 from Table 13 have the following ingredients inthe following ranges:

SiO₂ 57.65 to 60.33 percent by weight; Al₂O₃ 12.22 to 13.40 percent byweight; CaO 22.00 to 24.15 percent by weight; MgO 2.30 to 3.40 percentby weight; TiO₂ 0.50 to 1.50 percent by weight; Na₂O up to 0.45 percentby weight; Li₂O 0.45 to 1.00 percent by weight, and Fe₂O₃ up to 0.25percent by weight.

The ranges for the mathematical relationships of the ingredients ofExamples 123, 124, 125, 127–132, 147, 153, 155, 157, 160 and 161 fromTable 13 are as follows:

RO 24.84 to 26.70 wt % SiO₂/CaO 2.39 to 2.72 SiO₂/RO 2.16 to 2.42SiO₂/Al₂O₃ 4.30 to 4.92 Al₂O₃/CaO 0.52 to 0.59 SiO₂ + Al₂O₃ 71.05 to72.80 wt % SiO₂ − RO 31.35 to 35.37 wt % Al₂O₃/RO 0.47 to 0.52 R2O + RO25.74 to 27.60 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.30 to 2.81

The glass compositions have a log 3 forming temperature in the range of1205 to 1220° C. and in the range of 1205 to 1218° C., and a ΔT in therange of equal to and greater than 50° C. and equal to and less than 60°C.

The selection of the above examples is made based on the low formingtemperature. As can be appreciated, if a high delta T is of interestthen Examples 135-141, for example, would be of interest because theyhave a delta T in the range of 77-100° C.

The glass compositions of Examples 135–141 from Table 13 have thefollowing ingredients in the following ranges:

SiO₂ 59.55 to 60.57 percent by weight; Al₂O₃ 12.25 to 13.10 percent byweight; CaO 22.31 to 23.85 percent by weight; MgO 1.70 to 3.10 percentby weight; Na2O up to 0.30 percent by weight TiO₂ 1.10 percent byweight, and Li₂O up to 0.60 percent by weight.

The ranges for the mathematical relationships of the ingredients ofExamples 135–141 from Table 13 is as follows:

RO 24.01 to 25.95 wt % SiO₂/CaO 2.50 to 2.71 SiO₂/RO 2.29 to 2.52SiO₂/Al₂O₃ 4.62 to 4.88 Al₂O₃/CaO 0.52 to 0.59 SiO₂ + Al₂O₃ 71.80 to73.67 wt % SiO₂ − RO 33.60 to 36.56 wt % Al₂O₃/RO 0.47 to 0.55 R2O + RO24.91 to 26.85 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.67 to 2.96

The glass compositions have a log 3 forming temperature in the range of1234 to 1240° C., and a ΔT is in the range of 61 to 100° C.

Tables 14 and 15 (Type 4 Glasses) include glass compositions of aquaternary system that includes SiO₂ in the range of 55–62 wt %,preferably in the range of 56–61 wt % and more preferable in the rangeof 57–60 wt %; Al₂O₃ in the range of 10–14 wt %, preferably in the rangeof 11–14 wt % and more preferably in the range of 12–13.75 wt %; CaO inthe range of 21–26 wt %, preferable in the range of 21.50–25.00 wt % andmore preferable in the range of 21.75–24.50 wt %, and MgO in the rangeof 1–3.25 wt %, preferably in the range of 1.50–3.00 wt % and morepreferably in the range of 1.75–2.75 wt %. The compositions of Tables 14and 15 are boron free. The compositions of Tables 14 and 15 contemplateTiO₂ in the range of 0.25–1.75 wt %, more likely in the range of0.40–1.50 wt % and most likely in the range of 0.45–1.25 wt %; Li₂O inamounts in the range of 0.25 to 1.25 wt %, preferably in the range of0.30 to 1.10 wt %, and more preferably in the range of 0.40 to 1.00 wt%, ZnO in amounts in the range of 0.25 to 1.25 wt %, preferably in therange of 0.30 to 1.15 wt %, and more preferably in the range of 0.40 to1.10 wt %, and Fe₂O₃ in the range of up to 0.50 wt %, preferably up to0.35 wt % and more preferably up to 0.30 wt %.

A glass composition having ingredients of Tables 14 and 15 within theabove ranges and at least one of the following relationships provides aglass composition having a forming temperature below 1240° C. and adelta T of greater than 50° C.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 24 to 28 wt %25.25 to 27.00 wt % SiO₂/CaO 2.10 to 2.80 2.30 to 2.60 SiO₂/RO 1.90 to2.55 2.10 to 2.55 SiO₂/Al₂O₃ 3.70 to 5.00 4.20 to 5.00 Al₂O₃/CaO 0.45 to0.65 0.50 to 0.60 SiO₂ + Al₂O₃ 68 to 73.7 wt % 70.8 to 72 wt % R₂O + RO25 to 30 wt % 26.0 to 28 wt % (SiO₂ + Al₂O₃)/(R₂O + RO) 2.00 to 3.002.30 to 3.00 SiO₂ − RO 26.5 to 36.60 wt % 30.5 to 36.60 wt % Al₂O₃/RO0.40 to 0.60 0.46 to 0.53

The Type 4 Glasses are shown only to have Li₂O; therefore for Type 4Glasses R2O is equal to the wt % of Li₂O.

As can be appreciated, each of the Tables 14 and 15 provides ranges forthe ingredients and the relationships. More particularly, the glasscompositions of Tables 14 and 15 from Tables 14 and 15 have thefollowing ingredients in the following ranges:

SiO₂ 57.35 to 59.618.30 percent by weight; Al₂O₃ 12.16 to 13.63 percentby weight; CaO 22.85 to 24.22 percent by weight; MgO 1.90 to 2.55percent by weight; TiO₂ 0.50 to 1.10 percent by weight; Li₂O 0.45 to0.90 percent by weight; ZnO 0.45 to 1.00 percent by weight, and Fe₂O₃ upto 0.25 percent by weight.in the range of 1195 to 1229° C., and a ΔT is in the range of 54 to 71°C. The ranges for the mathematical relationships of the ingredients ofthe glass compositions of Tables 14 and 15 are found on Table 21 underthe column entitled “Type 4 Glasses”. The glass compositions have a log3 forming temperature.

The glass compositions of Table 14 from Table 14 have the followingingredients in the following ranges:

SiO₂ 58.00 to 58.30 percent by weight; Al₂O₃ 13.03 to 13.33 percent byweight; CaO 22.85 to 23.84 percent by weight; MgO 2.50 to 2.55 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Li₂O 0.90 percent byweight; ZnO 1.00 percent by weight, and Fe₂O₃ up to 0.25 percent byweight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 14 from Table 14 are as follows:

RO 25.40 to 26.34 wt % SiO₂/CaO 2.43 to 2.54 SiO2/RO 2.20 to 2.29SiO₂/Al₂O₃ 4.36 to 4.47 Al₂O₃/CaO 0.55 to 0.58 SiO₂ + Al₂O₃ 71.13 to71.58 wt % SiO₂ − RO 31.66 to 32.75 wt % Al₂O₃/RO 0.49 to 0.52 R2O + RO26.30 to 27.24 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.61 to 2.71

The glass compositions have a log 3 forming temperature in the range of1204 to 1213° C., and a ΔT in the range of 56 to 71° C.

The glass compositions of Table 15 from Table 15 have the followingingredients in the following ranges:

SiO₂ 57.35 to 59.61 percent by weight; Al₂O₃ 12.16 to 13.63 percent byweight; CaO 23.14 to 24.22 percent by weight; MgO 1.90 to 2.55 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Li₂O 0.45 to 0.90percent by weight; ZnO 0.45 to 1.00 percent by weight, and Fe₂O₃ up to0.25 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 15 from Table 15 are as follows:

RO 25.64 to 26.60 wt % SiO₂/CaO 2.41 to 2.54 SiO₂/RO 2.18 to 2.29SiO₂/Al₂O₃ 4.26 to 4.90 Al₂O₃/CaO 0.50 to 0.59 SiO₂ + Al₂O₃ 70.55 to71.77 wt % SiO₂ − RO 31.15 to 33.61 wt % Al₂O₃/RO 0.47 to 0.53 R2O + RO26.45 to 27.50 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.60 to 2.71

The glass compositions of Table 15 have a log 3 forming temperature inthe range of 1195 to 1229° C., and a ΔT in the range of 54 to 59° C.

Table 16 (Type 5 Glasses) include glass compositions of a quaternarysystem that includes SiO₂ in the range of 55–62 wt %, preferably in therange of 56–61 wt % and more preferable in the range of 58–60 wt %;Al₂O₃ in the range of 10–14 wt %, preferably in the range of 11.00–13.5wt % and more preferably in the range of 11.75–13.25 wt %; CaO in therange of 21–25 wt %, preferable in the range of 21.25–24.00 wt % andmore preferable in the range of 21.25–23.00 wt %, and MgO in the rangeof 1–4.00 wt %, preferably in the range of 1.25–3.50 wt % and morepreferably in the range of 1.50–3.50 wt %. The compositions of Table 16are boron free. The compositions of Table 16 contemplate TiO₂ in therange of 0.50–2.00 wt %, more likely in the range of 0.50–1.50 wt % andmore preferably in the range of 0.75–1.25 wt %; Na₂O in amounts in nogreater than 2.00 wt %; preferably no greater than 1.50 wt %, and morepreferably no greater than 1.25 wt %; ZnO in amounts in the range of0.50 to 3.00 wt %, preferably in the range of 0.50 to 2.75 wt %, andmore preferably in the range of 0.75 to 2.50 wt %, and Fe₂O₃ in therange of up to 0.50 wt %, preferably in the range of up to 0.35 wt % andmore preferably in the range of up to 0.30 wt %.

A glass composition having ingredients of Table 16 within the aboveranges and at least one of the following relationships provides a glasscomposition having a forming temperature below 1240° C. and a delta T ofgreater than 50° C.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 23 to 28 wt %24.0 to 27.0 wt % SiO₂/CaO 2.10 to 2.80 2.30 to 2.80 SiO₂/RO 1.90 to2.55 2.10 to 2.55 SiO₂/Al₂O₃ 3.70 to 5.00 4.20 to 5.00 Al₂O₃/CaO 0.45 to0.65 0.45 to 0.60 SiO₂ + Al₂O₃ 66 to 73.7 wt % 70.8 to 73.7 wt % R2O +RO 25 to 28 wt % 26.0 to 27.0 wt % (SiO₂ + Al₂O₃)/(R2O + RO) 2.00 to3.00 2.30 to 3.0 SiO₂ − RO 30 to 39 wt % 31.50 to 37. wt % Al₂O₃/RO 0.40to 0.60 0.46 o 0.53

Type 5 Glasses were considered having Na₂O; therefore R2O is equal tothe sum of Na₂O in wt %.

As can be appreciated, Table 16 provides ranges for the ingredients andthe relationships. More particularly, the glass compositions of Table 16from Table 16 have the following ingredients in the following ranges:

SiO₂ 58.70 to 59.00 percent by weight; Al₂O₃ 11.90 to 12.00 percent byweight; CaO 22.40 to 22.50 percent by weight; MgO 3.40 percent byweight; TiO₂ 1.00 percent by weight; Na₂O 0.90 percent by weight; ZnO1.00 to 1.50 percent by weight, and Fe₂O₃ up to 0.20 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Table 16 from Table 16 are on Table 21 under thecolumn entitled “Type 5 Glasses”. The glass compositions of Table 16have a log 3 forming temperature in the range of 1231 to 1234° C., and aΔT in the range of 50 to 59° C.

Tables 17 and 18 (Type 6 Glasses) include glass compositions of aquaternary system that includes SiO₂ in the range of 50–62 wt %,preferably in the range of 52–61 wt % and more preferable in the rangeof 53.50–60.25 wt %; Al₂O₃ in the range of 10–14 wt %, preferably in therange of 11.00–14.00 wt % and more preferably in the range of11.90–13.75 wt %; CaO in the range of 21–26 wt %, preferable in therange of 22.00–25.00 wt % and more preferable in the range of22.50–24.25 wt %, and MgO in the range of 1–4.00 wt %, preferably in therange of 1.50–3.00 wt % and more preferably in the range of 2.25–2.75 wt%. The compositions of Tables 17 and 18 have B₂O₃ in the range of0.50–5.00 wt %, preferably in the range of 0.50–4.00 and more preferablyin the range of 0.75–3.25 wt %. The compositions of Tables 17 and 18contemplate further include TiO₂ in the range of 0.25–2.00 wt %, morelikely in the range of 0.35–1.50 wt % and most likely in the range of0.40–1.25 wt %; Na₂O in amounts no greater than 1.00 wt %; preferably nogreater than 0.90 wt %, and more preferably no greater than 0.75 wt %;K₂O in amounts no greater than 0.50 wt %; preferably no greater than0.35 wt %, and more preferably no greater than 0.20 wt %; Li₂O inamounts in the range of 0.10 to 1.25 wt %, preferably in the range of0.20 to 1.10 wt %, and more preferably in the range of 0.25 to 1.00 wt%, and Fe₂O₃ in the range of 0.10–0.50 wt %, preferably in the range of0.15–0.50 wt % and more preferably in the range of 0.20–0.40 wt %.

A glass composition having ingredients of Tables 17 and 18 within theabove ranges and at least one of the following relationships provides aglass composition having a forming temperature below 1240° C. and adelta T of greater than 50° C.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 24 to 28 wt %25.0 to 27.20 wt % SiO₂/CaO 2.10 to 2.80 2.20 to 2.70 SiO₂/RO 1.90 to2.55 1.90 to 2.40 SiO₂/Al₂O₃ 3.50 to 5.00 4.00 to 5.00 Al₂O₃/CaO 0.50 to0.60 0.50 to 0.60 SiO₂ + Al₂O₃ 66 to 73.7 wt % 67 to 72.1 wt % R2O +RO + B₂O₃ 25 to 32 wt % 26.50 to 32 wt % (SiO₂ + Al₂O₃)/ 2.00 to 3.252.30 to 3.00 (R₂O + RO + B₂O₃) SiO₂ − RO 26.5 to 36.6 wt % 27 to 36.6 wt% Al₂O₃/RO 0.40 to 0.60 0.46 to 0.56

Type 6 Glasses of Tables 17 and 18 included Li₂O, K₂O and Na₂O;therefore R2O is equal to the sum in wt % of Li₂O, K₂O and Na₂O.Individual Table 17 includes Li₂O and Na₂O; therefore R2O for Table 17is equal to the sum in wt % of Li₂O and Na₂O. Individual Table 18includes Li₂O, K₂O and Na₂O; therefore R₂O for Table 18 is equal to thesum in wt % of Li₂O, K₂O and Na₂O.

As can be appreciated, Tables 17 and 18 provide ranges for theingredients and the relationships. More particularly, the glasscompositions of Tables 17 and 18 have the following ingredients in thefollowing ranges:

SiO₂ 54.60 to 59.53 percent by weight; Al₂O₃ 12.16 to 13.63 percent byweight; CaO 22.87 to 24.05 percent by weight; MgO 2.00 to 2.55 percentby weight; TiO₂ 0.49 to 1.10 percent by weight; Na₂O 0 to 0.60 percentby weight; K₂O 0 to 0.10 percent by weight; Li₂O 0.30 to 0.91 percent byweight; Fe₂O₃ 0.23 to 0.30 percent by weight, and B₂O₃ 0.90 to 3.00percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Tables 17 and 18 are on Table 21 under the columnentitled “Type 6 Glasses”. The glass compositions of Table 17 and 18have a log 3 forming temperature in the range of 1187 to 1239° C., and aΔT in the range of 50 to 142° C.

The glass compositions of Table 17 have the following ingredients in thefollowing ranges:

SiO₂ 57.60 to 58.50 percent by weight; Al₂O₃ 12.76 to 13.43 percent byweight; CaO 23.40 to 23.84 percent by weight; MgO 2.50 percent byweight; TiO₂ 0.50 percent by weight; Na₂O up to 0.60 percent by weight;Li₂O 0.90 percent by weight; Fe₂O₃ 0.23 percent by weight, and B₂O₃ 1.00to 1.20 percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Tables 17 are as follows:

RO 25.90 to 26.34 wt % SiO₂/CaO 2.42 to 2.48 SiO₂/RO 2.19 to 2.24SiO₂/Al₂O₃ 4.30 to 4.47 Al₂O₃/CaO 0.54 to 0.57 SiO₂ + Al₂O₃ 70.83 to71.47 wt % SiO₂ − RO 31.26 to 32.39 wt % Al₂O₃/RO 0.49 to 0.52 R2O +RO + B₂O₃ 27.80 to 28.44 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.49 to2.57

Type 6 Glasses of Table 17 included Li₂O, K₂O and Na₂O; therefore R₂O isequal to the sum in wt % of Li₂O, K₂O and Na₂O.

The glass compositions of Table 17 have a log 3 forming temperature inthe range of 1192 to 1198° C., and a ΔT in the range of 55 to 63° C.

The glass compositions of Table 18 have the following ingredients in thefollowing ranges:

SiO₂ 54.60 to 59.53 percent by weight; Al₂O₃ 12.16 to 13.63 percent byweight; CaO 22.93 to 24.05 percent by weight; MgO 2.00 to 2.55 percentby weight; TiO₂ 0.49 to 1.10 percent by weight; Na₂O up to 0.60 percentby weight; K₂O up to 0.10 percent by weight; Li₂O 0.30 to 0.91 percentby weight; Fe₂O₃ 0.23 to 0.35 percent by weight, and B₂O₃ 0.60 to 3.00percent by weight.

The ranges for the mathematical relationships of the ingredients of theglass compositions of Tables 17 are as follows:

RO 25.80 to 26.60 wt % SiO₂/CaO 2.22 to 2.66 SiO₂/RO 2.01 to 2.39SiO₂/Al₂O₃ 4.09 to 4.90 Al₂O₃/CaO 0.51 to 0.59 SiO₂ + Al₂O₃ 67.95 to72.05 wt % SiO₂ − RO 27.50 to 33.84 wt % Al₂O₃/RO 0.46 to 0.53 R2O +RO + B₂O₃ 26.70 to 31.10 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.18 to2.68

The glass compositions of Table 18 have a log 3 forming temperature inthe range of 1187 to 1239° C., and a ΔT in the range of 50 to 42° C.

The glass compositions listed on Table 18 and the glasses within thescope of the embodiment of Table 18 have a forming temperature in therange of 1187 to 1239° C. and a delta T in the range of 50–142° C.;however the preferred glass compositions from Table 18 are those thatprovide the forming temperature range 1187 to 1220° C. (Examples188–213, 215–229, 213–235, 238–240, 242–260 and 262–267) and morepreferably in the range of 1187–1205° C. (Examples 188–191, 194, 195,198, 200, 201, 202–205, 208, 209, 211–213, 215–219, 221–223, 225–229,233–235, 239, 242, 257 and 260).

A glass composition having the ingredients in the ranges mentioned abovefor Table 18 and having the following relationships will provide glasscompositions having a log 3 forming temperature in the range of 1187 to1220° C., and a ΔT is in the range of 50 to 139° C.:

RO 25.80 to 26.60 wt % SiO₂/CaO 2.22 to 2.66 SiO₂/RO 2.01 to 2.39SiO₂/Al₂O₃ 4.09 to 4.87 Al₂O₃/CaO 0.51 to 0.59 SiO₂ + Al₂O₃ 67.95 to72.05 wt % SiO₂ − RO 27.50 to 33.84 wt % Al₂O₃/RO 0.46 to 0.53 R2O +RO + B₂O₃ 26.70 to 31.10 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.18 to2.68

The glass compositions from Table 18 having a log 3 forming temperaturein the range of 1187 to 1205° C., and a ΔT in the range of 50 to 124° C.have the following ingredients and the following ranges:

SiO₂ 57.60 to 59.21 percent by weight; Al₂O₃ 12.16 to 13.63 percent byweight; CaO 22.87 to 24.06 percent by weight; MgO 2.36 to 2.50 percentby weight; TiO₂ 0.49 to 1.10 percent by weight; Na₂O up to 0.30 percentby weight; K₂O up to 0.09 percent by weight; Li₂O 0.70 to 0.90 percentby weight; Fe₂O₃ 0.23 to 0.29 percent by weight, and B₂O₃ 1.00 to 1.20percent by weight;And the following relationships:

RO 25.23 to 26.54 wt % SiO₂/CaO 2.40 to 2.57 SiO₂/RO 2.17 to 2.32SiO₂/Al₂O₃ 4.26 to 4.87 Al₂O₃/CaO 0.52 to 0.59 SiO₂ + Al₂O₃ 70.63 to71.73 wt % SiO₂ − RO 31.06 to 33.61 wt % Al₂O₃/RO 0.47 to 0.53 R2O +RO + B₂O₃ 27.23 to 28.64 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.47 to2.63

The selection of these examples is made based on the low formingtemperature. Further examples 266–268 are glass compositions that have alow forming temperature with 0.30 wt % Li₂O. Examples 265–268 define arange of ingredients and relationship of the ingredients to provide alow Li₂O containing glass with low forming temperature. As can beappreciated and as previously discussed, if a high delta T is ofinterest then Examples from Table 18 have a high delta T, e.g. above 75°C. may be selected to define glass compositions.

Table 19 (Type 7 Misc. Glasses) includes glass compositions of aquaternary system that includes SiO₂ in the range of 56–60 wt %,preferably in the range of 57–59 wt % and more preferable in the rangeof 57.50–59 wt %; Al₂O₃ in the range of 10–14 wt %, preferably in therange of 11.00–14.00 wt % and more preferably in the range of11.50–14.00 wt %; CaO in the range of 21–25 wt %, preferable in therange of 22.00–24.00 wt % and more preferable in the range of22.50–24.00 wt %, and MgO in the range of 2.00–4.00 wt %, preferably inthe range of 2.00–3.00 wt % and more preferably in the range of2.25–2.75 wt %. The compositions of Table 19 include B₂O₃ in the rangeof 0–1.50 wt %, preferably in the range of 0–1.25 wt % and morepreferably in the range of 0–1.10 wt %. The compositions of Table 19contemplates further includes TiO₂ in the range of 0.25–1.50 wt %, morelikely preferably in the range of 0.25–1.35 wt % and most likely in therange of 0.40–1.25 wt %; Na₂O in amounts no greater than 1.25 wt %;preferably no greater than 1.10 wt %, and more preferably no greaterthan 1.00 wt %; ZnO in amounts no greater than 0.50 wt %; preferably nogreater than 0.40 wt %, and more preferably no greater than 0.35 wt %;MnO in amounts no greater than 4.00 wt %; preferably no greater than3.50 wt %, and more preferably no greater than 3.25 wt %; MnO₂ inamounts no greater than 4.00 wt %; preferably no greater than 3.50 wt %,and more preferably no greater than 3.25 wt %, and Fe₂O₃ in the range of0.10–0.50 wt %, preferably in the range of 0.15–0.50 wt % and morepreferably in the range of 0.20–0.40 wt %.

A glass composition having ingredients of Tables 19 within the aboveranges and at least one of the following relationships provides a glasscomposition having a forming temperature below 1240° C. and a delta T ofgreater than 50° C.:

Relationship Broad Range Preferred Range RO (CaO + MgO) 24 to 27 wt %25.00 to 26.50 wt % SiO₂/CaO 2.10 to 2.80 2.20 to 2.70 SiO₂/RO 1.90 to2.55 1.90 to 2.40 SiO₂/Al₂O₃ 3.70 to 5.00 3.70 to 4.90 Al₂O₃/CaO 0.45 to0.65 0.55 to 0.60 SiO₂ + Al₂O₃ 66 to 73.7 wt % 66 to 72.1 wt % R₂O +RO + B₂O₃ 25 to 28 wt % 25.75 to 27.50 wt % (SiO₂ + Al₂O₃)/ 2.00 to 3.002.00 to 2.75 (R₂O + RO + B₂O₃) SiO₂ − RO 26.50 to 36.6 wt % 26.5 to34.00 wt % Al₂O₃/RO 0.40 to 0.60 0.46 to 0.56The Misc. Glasses included Li₂O and Na₂O; therefore R2O is equal to thesum in wt % of Li₂O and Na₂O.

Table 19 provides the following ranges for the following ingredients:

SiO₂ 57.72 to 58.70 percent by weight; Al₂O₃ 11.88 to 13.35 percent byweight; CaO 22.80 to 23.50 percent by weight; MgO 2.43 to 2.50 percentby weight; TiO₂ 0.50 to 1.10 percent by weight; Na₂O₃ 0.87–0.90 percentby weight; Li2O 0 to 0.30 percent by weight; ZnO 0 to 0.30 percent byweight; Fe₂O₃ 0.22–0.25 percent by weight; MnO 0.30 to 3.00 percent byweight; MnO₂ 0 to 3.00 percent by weight, and B₂O₃ 0 to 1.00 percent byweight.

The relationships for the ingredients of the glass compositions on Table19 are as follows:

RO 25.23 to 26.00 wt % SiO₂/CaO 2.49 to 2.54 SiO₂/RO 2.25 to 2.29SiO₂/Al₂O₃ 4.40 to 4.90 Al₂O₃/CaO 0.52 to 0.57 SiO₂ + Al₂O₃ 69.52 to72.05 wt % SiO₂ − RO 32.40 to 32.70 wt % Al₂O₃/RO 0.47 to 0.51 R2O +RO + B₂O₃ 26.10 to 27.30 wt % (SiO₂ + Al₂O₃)/(R2O + RO + B₂O₃) 2.59 to2.74The glass compositions have a log 3 forming temperature of in the rangeof 1219 to 1241° C., and a ΔT in the range of 52 to 76° C.

Table 20 (Production Glasses) Table 20 is a representation of commercialglasses having embodiments of the invention similar to the embodiment ofthe glass compositions of Table 4. The glass compositions are of aquaternary system that includes SiO₂ in the range of 55.97–57.07 wt %;Al₂O₃ in the range of 12.68–12.86 wt %; CaO in the range of 23.91–24.69wt % and MgO in the range of 2.42–2.60 wt %. The compositions of Table20 include B₂O₃ in the range of 1.15–1.70 wt %; TiO₂ in the range of0.94–1.09 wt %; Na₂O in the range of 0.87–0.93 wt %; K₂O in the range ofgreater than 0.050–0.070 wt %; SrO in the range of 0.040–0.050 wt %;Cr₂O₃ in the range of 0.002–0.008 wt %; SO₃ in the range of 0.018–0.032wt %, and Fe₂O₃ in the range of 0.255–0.278 wt %.

A glass composition having ingredients of Tables 20 within the aboveranges and at least one of the following relationships provides a glasscomposition having a forming temperature in the range of 1203–1217° C.and a delta T in the range of 55–83° C. Several of the glasscompositions do not have the forming and liquidus temperatures, and thedelta T. The glass compositions without the temperatures and delta Twere glass compositions made between glass compositions whose formingtemperature, liquidus temperature and delta T were measured. Asindicated by the position on the Table which is in general inchronological order, it is expected that the glass compositions notmeasured would have temperature performances similar to those that weremeasured. The mathematical relationships of the ingredients of the glasscompositions on Table 20 are listed on Table 22 in the column entitled“Production Glasses (contain boron)”. The R2O from the listed ProductionGlasses is equal to the sum in wt % of Li₂O and Na₂O.

As can now be appreciated, a range for each of the ingredients of theglass compositions of Types 1 and 2 glasses (Tables 2–11) can bedetermined from Tables. More particularly, Tables 1 and 2 provide aquaternary system including SiO2, Al203, CaO and MgO and the ingredientsof the glass having the relationship as shown in Table 22 under thecolumn entitled “Types 1 & 2 Glasses”. Types 1 & 2 Glasses included K₂Oand Na₂O; therefore R2O is equal to the sum in wt % of K₂O and Na₂O.

The glass compositions having the following ingredients in the followingranges has a log 3 forming temperature in the range of 1167 to 1240° C.and a ΔT in the range of 50 to 100° C.:

SiO₂ 53.00 to 59.05 percent by weight; Al₂O₃ 12.20 to 14.00 percent byweight; CaO 22.25 to 24.95 percent by weight, and MgO 1.50 to 3.00percent by weight, andthe composition may further include:

TiO₂ 0.50 to 1.10 percent by weight; Na₂O 0.45 to 0.90 percent byweight; K₂O 0 to 0.58 percent by weight; Fe₂O₃ 0 to 0.50 percent byweight, and B₂O₃ 0 to 5.02 percent by weight.

Further as can be appreciated, a range for each of the ingredients forType 3–6 glasses on Tables 12–19 can be determined by selecting thelowest and highest values to define the range for an ingredient and/orrelationship on Tables 12–19. More particularly Tables 12–19 provideglass compositions having a quaternary system including SiO₂, Al₂O₃, CaOand Mgo with the ingredients of the glass having the relationship shownon Table 22 under the column entitled “Types 3–6 Glasses”. Types 3–6Glasses included Li₂O, K₂O and Na₂O; therefore R2O is equal to the sumin wt % of Li₂O, K₂O and Na₂O.

The glass composition having the following ingredients in the followingranges has a log 3 forming temperature in the range of 1187 to 1240° C.and a delta T in the range of 50 to 142° C.:

SiO₂ 54.60 to 60.75 percent by weight; Al₂O₃ 11.90 to 13.64 percent byweight; CaO 22.00 to 24.22 percent by weight, and MgO 1.90 to 3.40percent by weight, andthe composition may further include:

TiO₂ 0.49 to 1.50 percent by weight; Na₂O 0 to 0.90 percent by weight;K₂O 0 to 0.10 percent by weight; ZnO 0.45 to 1.50 percent by weight;Li2O 0.30 to 1.00 percent by weight; Fe₂O₃ 0 to 0.35 percent by weight,and B₂O₃ 0 to 3.00 percent by weight.

Still further as can be appreciated, a range for each of the ingredientsfor boron free glasses: Type 1 Glasses (Table 2), Type 3 Glasses (Tables12 and 13); Type 4 Glasses (Tables 14 and 15); Type 5 Glasses (Table 16)and their relationship can be determined from Tables 2 and 12–16. Moreparticularly, Tables 2 and 12–16 glass compositions having a quaternarysystem including SiO₂, Al₂O₃, CaO and Mgo with the ingredients of theglass having the relationship shown on Table 22 under the columnentitled “Types 1 & 3–5 Glasses”. Types 1 & 3–5 Glasses included Li₂Oand Na₂O; therefore R2O is equal to the sum in wt % of Li₂O and Na₂O.Further Types 13&5 Glasses are boron free, therefore the formula“R2O+RO+B₂O₃” becomes “R2O+RO”.

The glass compositions having the following ingredients in the followingranges has a log 3 forming temperature in the range of 1195 to 1240° C.and a delta T in the range of 50 to 100° C.:

SiO₂ 57.45 to 60.75 percent by weight; Al₂O₃ 12.00 to 13.68 percent byweight; CaO 22.00 to 24.50 percent by weight; MgO 1.70 to 3.10 percentby weight, andthe composition may further include:

TiO₂ 0.50 to 1.50 percent by weight; Na₂O 0 to 0.91 percent by weight;ZnO 0 to 1.00 percent by weight; Li2O 0 to 1.00 percent by weight, andFe₂O₃ 0 to 0.35 percent by weight.

Still further as can be appreciated, a range for each of the ingredientsfor boron containing: Type 2 Glasses (Tables 3–11) and Type 6 Glasses(Tables 17 and 18) and their relationship can be determined from Tables3–11, 17 and 18. More particularly, Tables 3–11, 17 and 18 glasscompositions having a boron containing (for example up to 5.05 wt %)quaternary system including SiO₂, Al₂O₃, CaO and MgO with theingredients of the glass having the relationship shown on Table 22 underthe column entitled “Types 2 & 6 Glasses”. Types 2 & 6 Glasses includedLi₂O, K₂O and Na₂O; therefore R2O is equal to the sum in wt % of Li₂O,K₂O and Na₂O.

The glass compositions having the following ingredients in the followingranges has a log 3 forming temperature in the range of 1167 to 1240° C.and a delta T in the range of 50 to 142° C.:

SiO₂ 53.00 to 59.53 percent by weight; Al₂O₃ 12.00 to 14.00 percent byweight; CaO 22.25 to 24.95 percent by weight, and MgO 1.50 to 3.00percent by weight, andthe composition may further include:

TiO₂ 0.40 to 1.10 percent by weight; Na₂O 0 to 0.90 percent by weight;K₂O 0 to 0.30 percent by weight; F 0 to 0.50 percent by weight; SrO 0 to0.13 percent by weight; Cr2O3 0 to 0.13 percent by weight; Li2O 0 to0.91 percent by weight, and Fe₂O₃ 0 to 0.30 percent by weight.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. For example, but not limiting thereto, one,two, three or more or all of the formulas discussed above setting forththe mathematical relationship of the ingredients may be used to identifyproperties of a glass composition. Based on the description of theembodiments of the invention, it can be appreciated that this inventionis not limited to the particular embodiments disclosed, but it isintended to cover modifications that are within the spirit and scope ofthe invention, as defined by the appended claims.

TABLE 1 Examples Components (wt %) A B C D E F G SiO₂ 55.60 56.45 55.7057.60 56.35 56.70 57.85 Al₂O₃ 13.58 13.25 13.94 12.35 13.45 13.67 12.55CaO 24.76 24.75 24.80 24.40 24.65 23.87 24.45 MgO 2.80 2.55 2.55 2.552.55 2.62 2.55 TiO₂ 0.55 0.55 0.55 0.55 0.55 0.34 0.05 Na₂O 0.45 0.450.45 0.45 0.45 0.44 0.45 K₂O 0.58 0.45 0.45 0.45 0.45 0.51 0.45 Fe₂O₃0.38 0.25 0.25 0.25 0.25 0.35 0.35 B₂O₃ 1.30 1.30 1.30 1.30 1.30 1.501.30 RO (CaO + MgO) 27.56 27.30 27.35 26.95 27.20 26.49 27.00 SiO₂/CaO2.25 2.28 2.25 2.36 2.29 2.38 2.37 SiO₂/RO 2.02 2.07 2.04 2.14 2.07 2.142.14 SiO₂/Al₂O₃ 4.09 4.26 4.00 4.66 4.19 4.15 4.61 Al₂O₃/CaO 0.55 0.540.56 0.51 0.55 0.57 0.51 SiO₂ + Al₂O₃ 69.18 69.70 69.64 69.95 69.8070.37 70.44 R2O + RO + B₂O₃ 29.89 29.50 29.55 29.15 29.40 28.94 29.20(Si + Al)/(R2O + RO + B) 2.31 2.36 2.36 2.40 2.37 2.43 2.41 SiO₂ − RO28.04 29.15 28.35 30.65 29.15 30.21 30.85 Al₂O₃/RO 0.49 0.49 0.51 0.460.49 0.52 0.46 Log3 FT, ° C. 1213 1220 1220 1221 1221 1218 1219 LiquidusT, ° C. 1159 1160 1165 1164 1156 1160 1167 Delta T, ° C. 54 60 55 57 6558 52

TABLE 2 Type 1 Glasses Examples Components (wt %) H I 1 2 3 4 5 6 SiO₂57.60 58.18 57.75 57.45 57.65 58.05 57.95 59.05 Al₂O₃ 13.55 13.68 13.2013.40 13.40 13.40 13.20 12.20 CaO 24.50 23.75 24.25 24.35 24.15 23.7524.05 23.95 MgO 2.55 2.58 2.55 2.55 2.55 2.55 2.55 2.55 TiO₂ 0.55 0.551.10 1.10 1.10 1.10 1.10 1.10 Na₂O 0.90 0.91 0.90 0.90 0.90 0.90 0.900.90 Fe₂O₃ 0.35 0.35 0.25 0.25 0.25 0.25 0.25 0.25 B₂O₃ — — — — — — — —RO (CaO + MgO) 27.05 26.33 26.80 26.90 26.70 26.30 26.60 26.50 SiO₂/CaO2.35 2.45 2.38 2.36 2.39 2.44 2.41 2.47 SiO₂/RO 2.13 2.20 2.15 2.14 2.162.21 2.18 2.23 SiO₂/Al₂O₃ 4.25 4.25 4.38 4.29 4.30 4.33 4.39 4.84Al₂O₃/CaO 0.55 0.58 0.54 0.55 0.56 0.56 0.55 0.51 SiO₂ + Al₂O₃ 71.1571.86 70.95 70.85 71.05 71.45 71.15 71.25 R2O + RO + B₂O₃ 27.95 27.2427.70 27.80 27.60 27.20 27.50 27.40 (Si + Al)/(R2O + RO + B) 2.55 2.642.56 2.55 2.57 2.63 2.59 2.60 SiO₂ − RO 30.55 31.85 30.95 30.55 30.9531.75 31.35 32.55 Al₂O₃/RO 0.50 0.52 0.49 0.50 0.50 0.51 0.50 0.46 Log3FT, ° C. 1240 1238 1232 1238 1240 1240 1235 1239 Liquidus T, ° C. 11851183 1166 1165 1166 1167 1164 1181 Delta T, ° C. 55 55 66 73 74 73 71 58

TABLE 3 Type 2 Glasses Examples Components (wt %) 7 8 9 10 11 12 SiO₂56.00 56.40 56.35 56.65 56.20 56.50 Al₂O₃ 13.60 13.40 13.60 13.05 13.6013.20 CaO 24.25 24.05 23.85 23.50 24.05 23.50 MgO 2.50 2.50 2.55 2.552.50 2.55 TiO₂ 0.50 0.50 0.50 1.10 0.50 1.10 Na₂O 0.90 0.90 0.90 0.900.90 0.90 Fe₂O₃ 0.25 0.25 0.25 0.25 0.25 0.25 B₂O₃ 2.00 2.00 2.00 2.002.00 2.00 RO (CaO + MgO) 26.75 26.55 26.40 26.05 26.55 26.05 SiO₂/CaO2.31 2.35 2.36 2.41 2.34 2.40 SiO₂/RO 2.09 2.12 2.13 2.17 2.12 2.17SiO₂/Al₂O₃ 4.12 4.21 4.14 4.34 4.13 4.28 Al₂O₃/CaO 0.56 0.56 0.57 0.560.57 0.56 SiO₂ + Al₂O₃ 69.60 69.80 69.95 69.70 69.80 69.70 R2O + RO +B₂O₃ 29.65 29.45 29.30 28.95 29.45 28.95 (Si + Al)/(R2O + RO + B) 2.352.37 2.39 2.41 2.37 2.41 SiO₂ − RO 29.25 29.85 29.95 30.60 29.65 30.45Al₂O₃/RO 0.51 0.50 0.52 0.50 0.51 0.51 Log3 FT, ° C. 1213 1216 1218 12181219 1220 Liquidus T, ° C. 1136 1143 1138 1131 1136 1133 Delta T, ° C.59 56 62 69 65 69

TABLE 4 Type 2 Glasses Examples Components (wt %) 13 14 15 16 17 18 1920 21 22 SiO₂ 56.25 56.45 56.75 56.50 56.75 57.5 56.75 57.75 57.75 57.75Al₂O₃ 13.2 13.20 13.20 13.20 13.20 12.2 13.2 12.2 12.2 12.2 CaO 24.2524.25 23.95 24.00 23.75 24 23.95 23.75 23.75 23.95 MgO 2.55 2.55 2.552.55 2.55 2.55 2.55 2.55 2.55 2.55 TiO₂ 1.10 1.10 1.10 1.10 1.10 1.101.10 1.10 1.10 1.10 Na₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.900.90 Fe₂O₃ 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 B₂O₃ 1.301.30 1.30 1.30 1.40 1.30 1.20 1.40 1.30 1.40 RO (CaO + MgO) 26.80 26.8026.50 26.55 26.30 26.55 26.50 26.30 26.30 26.50 SiO₂/CaO 2.32 2.33 2.372.35 2.39 2.40 2.37 2.43 2.43 2.41 SiO₂/RO 2.10 2.11 2.14 2.13 2.16 2.172.14 2.20 2.20 2.18 SiO₂/Al₂O₃ 4.26 4.28 4.30 4.28 4.30 4.71 4.30 4.734.73 4.73 Al₂O₃/CaO 0.54 0.54 0.55 0.55 0.56 0.51 0.55 0.51 0.51 0.51SiO₂ + Al₂O₃ 69.45 69.65 69.95 69.70 69.95 69.70 69.95 69.95 69.95 69.95R2O + RO + B₂O₃ 29.00 29.00 28.70 28.75 28.60 28.75 28.60 28.60 28.5028.80 (Si + Al)/(R2O + RO + B) 2.39 2.40 2.44 2.42 2.45 2.42 2.45 2.452.45 2.43 SiO₂ − RO 29.45 29.65 30.25 29.95 30.45 30.95 30.25 31.4531.45 31.25 Al₂O₃/RO 0.49 0.49 0.50 0.50 0.50 0.46 0.50 0.46 0.46 0.46Log3 FT, ° C. 1210 1214 1215 1215 1215 1216 1216 1217 1217 1218 LiquidusT, ° C. 1154 1159 1154 1154 1160 1152 1147 1151 1147 1155 Delta T, ° C.56 55 61 61 55 64 69 66 70 63

TABLE 5 Type 2 Glasses Examples Components (wt %) 23 24 25 26 27 28 2930 31 32 SiO₂ 55.40 55.40 55.19 55.40 56.05 55.85 56.00 55.90 55.4055.19 Al₂O₃ 13.60 13.60 13.59 13.60 13.10 13.38 13.37 13.37 13.80 13.59CaO 24.50 24.50 24.55 24.50 24.55 24.67 24.53 24.63 24.50 24.55 MgO 2.952.95 2.86 2.95 2.75 2.55 2.55 2.55 2.75 2.86 TiO₂ 1.10 1.10 1.10 1.101.10 1.10 1.10 1.10 1.10 1.10 Na₂O 0.45 0.45 0.45 0.45 0.45 0.45 0.450.45 0.45 0.45 K₂O 0.45 0.45 0.58 0.45 0.45 0.45 0.45 0.45 0.45 0.58Fe₂O₃ 0.25 0.25 0.38 0.25 0.25 0.25 0.25 0.25 0.25 0.38 B₂O₃ 1.30 1.301.30 1.30 1.30 1.30 1.30 1.30 1.30 1.30 RO (CaO + MgO) 27.45 27.45 27.4127.45 27.30 27.22 27.08 27.18 27.25 27.41 SiO₂/CaO 2.26 2.26 2.25 2.262.28 2.26 2.28 2.27 2.26 2.25 SiO₂/RO 2.02 2.02 2.01 2.02 2.05 2.05 2.072.06 2.03 2.01 SiO₂/Al₂O₃ 4.07 4.07 4.06 4.07 4.28 4.17 4.19 4.18 4.014.06 Al₂O₃/CaO 0.56 0.56 0.55 0.56 0.53 0.54 0.55 0.54 0.56 0.55 SiO₂ +Al₂O₃ 69.00 69.00 68.78 69.00 69.15 69.23 69.37 69.27 69.20 68.78 R2O +RO + B₂O₃ 29.65 29.65 29.74 29.65 29.50 29.42 29.28 29.38 29.45 29.74(Si + Al)/(R2O + RO + B) 2.33 2.33 2.31 2.33 2.34 2.35 2.37 2.36 2.352.31 SiO₂ − RO 27.95 27.95 27.78 27.95 28.75 28.63 28.92 28.72 28.1527.78 Al₂O₃/RO 0.50 0.50 0.50 0.50 0.48 0.49 0.49 0.49 0.51 0.50 Log3FT, ° C. 1210 1211 1216 1217 1218 1220 1221 1221 1221 1222 Liquidus T, °C. 1157 1151 1154 1167 1156 1148 1157 1142 1167 1154 Delta T, ° C. 53 6062 56 62 72 64 79 54 63

TABLE 6 Type 2 Glasses Examples Components (wt %) 33 34 35 36 37 38 3940 41 42 SiO₂ 56.60 56.50 56.50 55.95 57.60 56.50 56.45 56.50 56.5556.15 Al₂O₃ 13.25 13.45 13.45 13.95 12.35 13.49 13.48 13.45 13.35 13.35CaO 24.60 24.50 24.50 24.55 24.40 24.46 24.52 24.50 24.55 24.95 MgO 2.552.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 TiO₂ 0.55 0.55 0.55 0.550.55 0.55 0.55 0.55 0.55 0.55 Na₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.900.90 0.90 0.90 Fe₂O₃ 0.25 0.25 0.25 0.25 0.35 0.25 0.25 0.25 0.25 0.25B₂O₃ 1.30 1.30 1.30 1.30 1.30 1.30 1.30 1.30 1.30 1.30 RO (CaO + MgO)27.15 27.05 27.05 27.10 26.95 27.01 27.07 27.05 27.10 27.50 SiO₂/CaO2.30 2.31 2.31 2.28 2.36 2.31 2.30 2.31 2.30 2.25 SiO₂/RO 2.08 2.09 2.092.06 2.14 2.09 2.09 2.09 2.09 2.04 SiO₂/Al₂O₃ 4.27 4.20 4.20 4.01 4.664.19 4.19 4.20 4.24 4.21 Al₂O₃/CaO 0.54 0.55 0.55 0.57 0.51 0.55 0.550.55 0.54 0.54 SiO₂ + Al₂O₃ 69.85 69.95 69.95 69.90 69.95 69.99 69.9369.95 69.90 69.50 R2O + RO + B₂O₃ 29.35 29.25 29.25 29.30 29.15 29.2129.27 29.25 29.30 29.70 (Si + Al)/(R2O + RO + B) 2.38 2.39 2.39 2.392.40 2.40 2.39 2.39 2.39 2.34 SiO₂ − RO 29.45 29.45 29.45 28.85 30.6529.49 29.38 29.45 29.45 28.65 Al₂O₃/RO 0.49 0.50 0.50 0.51 0.46 0.500.50 0.50 0.49 0.49 Log3 FT, ° C. 1211 1212 1215 1216 1216 1218 12191220 1220 1220 Liquidus T, ° C. 1153 1158 1157 1162 1164 1161 1158 11601155 1154 Delta T, ° C. 58 54 58 54 52 57 61 60 65 66

TABLE 7 Type 2 Glasses Examples Components (wt %) 43 44 45 46 47 48 4950 51 52 SiO₂ 55.50 55.25 55.25 55.5 55.00 55.75 55.75 55.75 56.00 56.15Al₂O₃ 13.20 13.20 13.30 13.30 13.20 13.30 13.20 13.20 13.30 13.05 CaO23.50 23.75 24.20 23.95 24.00 23.70 23.25 23.25 23.45 23.00 MgO 2.552.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 TiO₂ 1.10 1.10 0.55 0.551.10 0.55 1.10 1.10 0.55 1.10 Na₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.900.90 0.90 0.90 Fe₂O₃ 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25B₂O₃ 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 RO (CaO + MgO)26.05 26.30 26.75 26.50 26.55 26.25 25.80 25.80 26.00 25.55 SiO₂/CaO2.36 2.33 2.28 2.32 2.29 2.35 2.40 2.40 2.39 2.44 SiO₂/RO 2.13 2.10 2.072.09 2.07 2.12 2.16 2.16 2.15 2.20 SiO₂/Al₂O₃ 4.20 4.19 4.15 4.17 4.174.19 4.22 4.22 4.21 4.30 Al₂O₃/CaO 0.56 0.56 0.55 0.56 0.55 0.56 0.570.57 0.57 0.57 SiO₂ + Al₂O₃ 68.70 68.45 68.55 68.80 68.20 69.05 68.9568.95 69.30 69.20 R2O + RO + B₂O₃ 29.95 30.20 30.65 30.40 30.45 30.1529.70 29.70 29.90 29.45 (Si + Al)/(R2O + RO + B) 2.29 2.27 2.24 2.262.24 2.29 2.32 2.32 2.32 2.35 SiO₂ − RO 29.45 28.95 28.50 29.00 28.4529.50 29.95 29.95 30.00 30.60 Al₂O₃/RO 0.51 0.50 0.50 0.50 0.50 0.510.51 0.51 0.51 0.51 Log3 FT, ° C. 1193 1198 1198 1200 1201 1201 12041204 1207 1212 Liquidus T, ° C. 1129 1122 1128 1129 1127 1127 1127 11231127 1122 Delta T, ° C. 64 76 70 71 74 74 77 81 80 90

TABLE 8 Type 2 Glasses Examples Components (wt %) 53 54 55 56 57 58 5960 61 62 63 SiO₂ 54.20 54.50 54.12 55.00 54.5 54.5 54.7 54.50 54.2054.50 54.80 Al₂O₃ 13.35 13.25 13.30 13.25 13.25 13.25 13.2 13.25 13.3513.25 13.25 CaO 24.55 24.55 24.55 24.25 24.55 24.55 24.5 24.55 24.5524.55 24.25 MgO 2.55 2.55 3.00 2.55 2.67 2.67 2.55 2.65 2.85 2.65 2.55TiO₂ 0.55 0.55 0.55 0.55 0.55 0.55 0.55 0.55 0.55 0.55 0.55 Na₂O 0.450.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 K₂O 0.55 0.55 0.550.55 0.55 0.55 0.55 0.55 0.55 0.55 0.55 Fe₂O₃ 0.28 0.28 0.28 0.28 0.280.28 0.28 0.28 0.28 0.28 0.28 B₂O₃ 3.00 3.00 3.00 3.00 3.00 3.00 3.003.00 3.00 3.00 3.00 F 0.20 0.20 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.100.20 SrO 0.12 0.12 0.10 0.12 0.10 0.10 0.12 0.12 0.12 0.12 0.12 RO(CaO + MgO) 27.10 27.10 27.55 26.80 27.22 27.22 27.05 27.20 27.40 27.2026.80 SiO₂/CaO 2.21 2.22 2.20 2.27 2.22 2.22 2.23 2.22 2.21 2.22 2.26SiO₂/RO 2.00 2.01 1.96 2.05 2.00 2.00 2.02 2.00 1.98 2.00 2.04SiO₂/Al₂O₃ 4.06 4.11 4.07 4.15 4.11 4.11 4.14 4.11 4.06 4.11 4.14Al₂O₃/CaO 0.54 0.54 0.54 0.55 0.54 0.54 0.54 0.54 0.54 0.54 0.55 SiO₂ +Al₂O₃ 67.55 67.75 67.42 68.25 67.75 67.75 67.90 67.75 67.55 67.75 68.05R2O + RO + B₂O₃ 31.10 31.10 31.55 30.80 31.22 31.22 31.05 31.20 31.4031.20 30.80 (Si + Al)/(R2O + RO + B) 2.17 2.18 2.14 2.22 2.17 2.17 2.192.17 2.15 2.17 2.21 SiO₂ − RO 27.10 27.40 26.57 28.20 27.28 27.28 27.6527.30 26.80 27.30 28.00 Al₂O₃/RO 0.49 0.49 0.48 0.49 0.49 0.49 0.49 0.490.49 0.49 0.49 Log3 FT, ° C. 1190 1194 1196 1197 1201 1199 1201 11961196 1197 1197 Liquidus T, ° C. 1120 1124 1132 1124 1131 1137 1119 11301130 1127 1121 Delta T, ° C. 70 70 64 73 70 62 82 66 66 70 76 ExamplesComponents (wt %) 64 65 66 67 68 69 70 71 721 73 74 SiO₂ 55.05 54.9554.20 55.25 54.8 55.25 54.95 54.75 54.55 54.80 54.70 Al₂O₃ 13.25 13.2513.35 13.30 13.25 13.30 13.25 13.20 13.40 13.20 13.30 CaO 24.20 24.324.55 24.20 24.25 24.20 24.30 24.45 24.45 24.40 24.40 MgO 2.55 2.55 2.852.55 2.55 2.55 2.55 2.55 2.55 2.55 2.55 TiO₂ 0.55 0.55 0.55 0.55 0.550.55 0.55 0.55 0.55 0.55 0.55 Na₂O 0.45 0.45 0.45 0.45 0.45 0.45 0.450.45 0.45 0.45 0.45 K₂O 0.55 0.55 0.55 0.45 0.55 0.45 0.55 0.55 0.550.55 0.55 Fe₂O₃ 0.28 0.28 0.28 0.25 0.28 0.25 0.28 0.28 0.28 0.28 0.28B₂O₃ 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 F 0.10 0.100.10 — 0.20 — — 0.10 0.10 0.10 0.10 SrO 0.12 0.12 0.12 — 0.12 — 0.120.12 0.12 0.12 0.12 RO (CaO + MgO) 26.75 26.85 27.40 26.75 26.80 26.7526.85 27.00 27.00 26.95 26.95 SiO₂/CaO 2.27 2.26 2.21 2.28 2.26 2.282.26 2.24 2.23 2.25 2.24 SiO₂/RO 2.06 2.05 1.98 2.07 2.04 2.07 2.05 2.032.02 2.03 2.03 SiO₂/Al₂O₃ 4.15 4.15 4.06 4.15 4.14 4.15 4.15 4.15 4.074.15 4.11 Al₂O₃/CaO 0.55 0.55 0.54 0.55 0.55 0.55 0.55 0.54 0.55 0.540.55 SiO₂ + Al₂O₃ 68.30 68.20 67.55 68.55 68.05 68.55 68.20 67.95 67.9568.00 68.00 R2O + RO + B₂O₃ 30.75 30.85 31.40 30.65 30.80 30.65 30.8531.00 31.00 30.95 30.95 (Si + Al)/(R2O + RO + B) 2.22 2.21 2.15 2.242.21 2.24 2.21 2.19 2.19 2.20 2.20 SiO₂ − RO 28.30 28.10 26.80 28.5028.00 28.50 28.10 27.75 27.55 27.85 27.75 Al₂O₃/RO 0.50 0.49 0.49 0.500.49 0.50 0.49 0.49 0.50 0.49 0.49 Log3 FT, ° C. 1198 1198 1199 12021202 1203 1203 1203 1203 1204 1204 Liquidus T, ° C. 1127 1123 1137 11261147 1124 1125 1125 1124 1121 1122 Delta T, ° C. 71 75 62 76 55 79 78 7879 83 82

TABLE 9 Type 2 Glasses Examples Components (wt %) 75 76 77 SiO₂ 53.0053.00 53.50 Al₂O₃ 13.10 13.50 14.00 CaO 24.00 24.00 24.00 MgO 2.50 2.501.50 TiO₂ 0.50 0.50 0.50 Na₂O 0.90 0.90 0.90 K₂O 0.37 0.37 0.37 Fe₂O₃0.10 0.10 0.10 B₂O₃ 5.02 4.93 4.94 F 0.50 0.50 0.50 SrO 0.13 0.13 0.13Cr₂O₃ 0.13 0.13 0.13 RO (CaO + MgO) 26.50 26.50 25.50 SiO₂/CaO 2.21 2.212.23 SiO₂/RO 2.00 2.00 2.10 SiO₂/Al₂O₃ 4.05 3.93 3.82 Al₂O₃/CaO 0.550.56 0.58 SiO₂ + Al₂O₃ 66.10 66.50 67.50 R2O + RO + B₂O₃ 32.79 32.7031.71 (Si + Al)/ 2.02 2.03 2.13 (R2O + RO + B) SiO₂ − RO 26.50 26.5028.00 Al₂O₃/RO 0.49 0.51 0.55 Log3 FT, ° C. 1167 1172 1177 Liquidus T, °C. 1110 1103 1122 Delta T, ° C. 57 69 57

TABLE 10 Type 2 Glasses Examples Components (wt %) 78 79 80 81 82 83 8485 86 87 88 89 SiO₂ 55.40 55.80 56.20 55.75 56.35 55.60 55.80 56.40 56.056.00 56.00 56.65 Al₂O₃ 13.60 13.40 13.60 13.20 13.60 13.60 13.60 13.4013.60 13.80 13.60 13.05 CaO 24.85 24.65 24.05 23.25 23.85 24.65 24.4524.05 24.25 24.05 24.25 23.50 MgO 2.50 2.50 2.50 2.55 2.55 2.50 2.502.50 2.50 2.50 2.50 2.55 TiO₂ 0.50 0.50 0.50 1.10 0.50 0.50 0.50 0.500.50 0.50 0.50 1.10 Na₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.900.90 0.90 0.90 Fe₂O₃ 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.250.25 0.25 B₂O₃ 2.00 2.00 2.00 3.00 2.00 2.00 2.00 2.00 2.00 2.00 2.002.00 RO 27.35 27.15 26.55 25.80 26.40 27.15 26.95 26.55 26.75 26.5526.75 26.05 SiO₂/CaO 2.23 2.25 2.34 2.40 2.36 2.26 2.28 2.35 2.31 2.332.31 2.41 SiO₂/RO 2.03 2.06 2.12 2.16 2.13 2.05 2.07 2.12 2.09 2.11 2.092.17 SiO₂/Al₂O₃ 4.07 4.16 4.13 4.22 4.14 4.09 4.10 4.21 4.12 4.06 4.114.34 Al₂O₃/CaO 0.54 0.54 0.57 0.57 0.57 0.55 0.56 0.55 0.56 0.57 0.560.56 SiO₂ + Al₂O₃ 69.00 69.20 69.80 68.95 69.95 69.20 69.40 69.80 69.6069.80 69.60 69.70 R2O + RO + B₂O₃ 30.25 30.05 29.45 29.70 29.30 30.0529.85 29.45 29.65 29.45 29.65 28.95 (Si + Al)/(R2O + RO + B) 2.28 2.302.37 2.32 2.39 2.30 2.32 2.37 2.35 2.37 2.35 2.41 SiO₂ − RO 28.05 28.6529.65 29.95 29.95 28.45 28.85 29.85 29.25 29.45 29.25 30.60 Al₂O₃/RO0.50 0.49 0.51 0.51 0.51 0.50 0.50 0.50 0.51 0.52 0.51 0.50 Log3 FT, °C. 1217 1211 1219 1204 1218 1211 1209 1216 1213 1219 1202 1218 LiquidusT, ° C. 1153 1156 1136 1127 1138 1154 1156 1143 1136 1151 1137 1131Delta T, ° C. 64 55 83 77 80 57 53 73 77 68 65 87 Examples Components(wt %) 90 91 92 93 94 95 96 97 98 99 SiO₂ 56.25 56.15 57.75 57.75 56.7557.15 57.25 58.55 57.25 56.25 Al₂O₃ 13.20 13.05 13.20 12.20 13.20 13.0513.20 12.20 12.20 13.20 CaO 23.25 23.00 24.25 24.25 24.25 24.00 24.2523.45 23.75 23.75 MgO 2.55 2.55 2.50 2.50 2.50 2.55 2.50 2.55 2.50 2.50TiO₂ 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.10 Na₂O 0.90 0.900.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 Fe₂O₃ 0.25 0.25 0.25 0.25 0.250.25 0.25 0.25 0.25 0.25 B₂O₃ 3.00 3.00 1.00 1.00 1.00 1.00 1.00 1.002.00 2.00 RO 25.80 25.55 26.75 26.75 26.75 26.55 26.75 26.00 26.25 26.25SiO₂/CaO 2.41 2.44 2.38 2.38 2.34 2.38 2.36 2.50 2.41 2.37 SiO₂/RO 2.182.20 2.16 2.16 2.12 2.15 2.14 2.25 2.18 2.14 SiO₂/Al₂O₃ 4.26 4.30 4.384.73 4.30 4.38 4.33 4.80 4.69 4.26 Al₂O₃/CaO 0.56 0.56 0.54 0.50 0.540.54 0.54 0.52 0.51 0.56 SiO₂ + Al₂O₃ 69.45 69.20 70.95 69.95 69.9570.20 70.45 70.75 69.45 69.45 R2O + RO + B₂O₃ 29.70 29.45 28.65 28.6528.65 28.45 28.65 27.90 29.15 29.15 (Si + Al)/(R2O + RO + B) 2.34 2.342.67 2.44 2.44 2.47 2.47 2.54 2.38 2.38 SiO₂ − RO 30.45 30.60 31.0031.00 30.00 30.60 30.50 32.55 31.00 30.00 Al₂O₃/RO 0.51 0.51 0.49 0.460.49 0.49 0.49 0.47 0.46 0.50 Log3 FT, ° C. 1214 1212 1240 1227 12281235 1239 1236 1227 1224 Liquidus T, ° C. 1114 1178 1178 1164 1161 11541159 1159 1148 1149 Delta T, ° C. 100 34 62 63 67 81 80 77 79 75Examples Components (wt %) 100 101 102 103 104 105 106 107 108 109 SiO₂56.65 56.75 58.05 55.80 57.25 56.75 56.25 56.50 55.80 56.75 Al₂O₃ 13.0513.20 12.20 13.60 13.20 13.20 13.20 13.20 13.80 13.20 CaO 23.50 23.2522.95 24.45 22.75 23.75 23.75 23.50 24.25 22.25 MgO 2.55 2.55 2.55 2.502.50 2.05 2.55 2.55 2.50 2.55 TiO₂ 1.10 1.10 1.10 0.50 1.10 1.10 1.101.10 0.50 1.10 Na₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90Fe₂O₃ 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 B₂O₃ 2.00 2.002.00 2.00 2.00 2.00 2.00 2.00 2.00 3.00 RO 26.05 25.80 25.50 26.95 25.2525.80 26.30 26.05 26.75 24.80 SiO₂/CaO 2.41 2.44 2.53 2.28 2.52 2.392.37 2.40 2.30 2.55 SiO₂/RO 2.17 2.20 2.28 2.07 2.27 2.20 2.14 2.16 2.092.29 SiO₂/Al₂O₃ 4.34 4.30 4.76 4.10 4.34 4.30 4.26 4.28 4.04 4.30Al₂O₃/CaO 0.56 0.57 0.53 0.56 0.58 0.56 0.55 0.56 0.57 0.59 SiO₂ + Al₂O₃69.70 69.95 70.25 69.40 70.45 69.95 69.45 69.70 69.60 69.95 R2O + RO +B₂O₃ 28.95 28.70 28.40 29.85 28.15 28.70 29.20 28.95 29.65 28.70 (Si +Al)/(R2O + RO + B) 2.41 2.44 2.47 2.32 2.50 2.44 2.38 2.41 2.35 2.44SiO₂ − RO 30.60 30.95 32.55 28.85 32.00 30.95 29.95 30.45 29.05 31.95Al₂O₃/RO 0.50 0.51 0.48 0.50 0.52 0.51 0.50 0.51 0.52 0.53 Log3 FT, ° C.1225 1225 1225 1222 1237 1230 1220 1220 1222 1221 Liquidus T, ° C. 11451147 1142 1153 1149 1141 1131 1133 1137 1121 Delta T, ° C. 80 78 83 6986 89 89 87 85 100

TABLE 11 Type 2 Glasses Examples Components (wt %) 110 111 112 SiO₂57.75 57.75 56.10 Al₂O₃ 12.2 12.2 13.38 CaO 23.75 23.95 24.42 MgO 2.552.55 2.55 TiO₂ 1.10 1.10 0.55 Na₂O 0.90 0.90 0.90 K₂O — — — Fe₂O₃ 0.250.25 0.25 B₂O₃ 1.40 1.40 1.30 RO (CaO + MgO) 26.30 26.50 26.97 SiO₂/CaO2.43 2.41 2.30 SiO₂/RO 2.20 2.18 2.08 SiO₂/Al₂O₃ 4.73 4.73 4.19Al₂O₃/CaO 0.51 0.51 0.54 SiO₂ + Al₂O₃ 69.95 69.95 69.48 R2O + RO + B₂O₃28.60 28.80 29.17 (Si + Al)/ 2.44 2.43 2.38 (R2O + RO + B) SiO₂ − RO31.45 31.25 29.13 Al₂O₃/RO 0.46 0.46 0.50 Log3 FT, ° C. 1217 1218 1215Liquidus T, ° C. 1151 1155 1150 Delta T, ° C. 66 63 65

TABLE 12 Type 3 Glasses Examples Components (wt %) 113 114 115 116 117118 119 120 121 SiO₂ 58.70 57.95 58.35 60.05 58.25 58.86 59.97 59.1658.76 Al₂O₃ 13.35 13.20 13.20 12.98 13.40 13.44 12.19 13.24 13.64 CaO23.50 24.05 23.65 22.14 23.55 23.55 22.25 23.45 23.45 MgO 2.50 2.55 2.553.12 2.55 2.50 2.90 2.50 2.50 TiO₂ 0.50 1.10 1.10 0.55 1.10 0.50 1.500.50 0.50 Na₂O 0.30 — — — — — — — — K₂O — — — — — — — — — Li₂O 0.90 0.900.90 0.91 0.90 0.90 0.90 0.90 0.90 Fe₂O₃ 0.20 0.25 0.25 0.25 0.25 0.250.25 0.25 0.25 B₂O₃ — — — — — — — — — RO (CaO + MgO) 26.00 26.60 26.2025.26 26.10 26.05 25.15 25.95 25.95 SiO₂/CaO 2.50 2.41 2.47 2.71 2.472.50 2.70 2.52 2.51 SiO₂/RO 2.26 2.18 2.23 2.38 2.23 2.26 2.38 2.28 2.26SiO₂/Al₂O₃ 4.40 4.39 4.42 4.63 4.35 4.38 4.92 4.47 4.31 Al₂O₃/CaO 0.570.55 0.56 0.59 0.57 0.57 0.55 0.56 0.58 SiO₂ + Al₂O₃ 72.05 71.15 71.5573.03 71.65 72.30 72.16 72.40 72.40 R2O + RO + B₂O₃ 27.20 27.50 27.1026.17 27.00 26.95 26.05 26.85 26.85 (Si + Al)/(R2O + RO + B) 2.65 2.592.64 2.79 2.65 2.68 2.77 2.70 2.70 SiO₂ − RO 32.70 31.35 32.15 34.7932.15 32.81 34.82 33.21 32.81 Al₂O₃/RO 0.51 0.50 0.50 0.51 0.51 0.520.48 0.51 0.53 Log3 FT, ° C. 1211 1205 1211 1214 1215 1216 1217 12181218 Liquidus T, ° C. 1153 1151 1146 1159 1153 1153 1161 1156 1150 DeltaT, ° C. 58 54 65 55 62 63 56 62 68

TABLE 13 Type 3 Glasses Examples Components (wt %) 122 123 124 125 126127 128 129 130 131 SiO₂ 58.70 59.30 57.65 58.96 58.15 60.09 60.21 60.3359.73 59.85 Al₂O₃ 13.35 12.10 13.40 13.24 13.20 12.22 12.24 12.27 12.9212.95 CaO 23.50 22.60 24.15 23.65 23.85 23.31 23.35 23.40 22.00 22.04MgO 2.50 3.40 2.55 2.50 2.55 2.70 2.50 2.30 3.10 2.90 TiO₂ 0.50 1.501.10 0.50 1.10 0.50 0.50 0.50 1.10 1.10 Na₂O 0.60 0.45 — — — — — — — —Li₂O 0.60 0.45 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 Fe₂O₃ 0.25 0.200.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 B₂O₃ — — — — — — — — — — RO(CaO + MgO) 26.00 26.00 26.70 26.15 26.40 26.01 25.85 25.70 25.10 24.94SiO₂/CaO 2.50 2.62 2.39 2.49 2.44 2.58 2.58 2.58 2.70 2.72 SiO₂/RO 2.262.28 2.16 2.25 2.20 2.31 2.33 2.35 2.38 2.40 SiO₂/Al₂O₃ 4.40 4.90 4.304.45 4.41 4.92 4.92 4.92 4.62 4.62 Al₂O₃/CaO 0.57 0.54 0.55 0.56 0.550.52 0.52 0.52 0.59 0.59 SiO₂ + Al₂O₃ 72.05 71.40 71.05 72.20 71.3572.31 72.45 72.60 72.65 72.80 R2O + RO + B₂O₃ 27.20 27.45 27.60 27.0527.30 26.91 26.75 26.60 26.00 25.84 (Si + Al)/(R2O + RO + B) 2.65 2.702.57 2.67 2.61 2.69 2.71 2.73 2.30 2.32 SiO₂ − RO 32.7 33.30 30.95 32.8131.75 34.08 34.36 34.63 34.63 34.91 Al₂O₃/RO 0.51 0.47 0.50 0.51 0.500.47 0.47 0.48 0.51 0.52 Log3 FT, ° C. 1226 1205 1206 1212 1237 12171213 1216 1214 1214 Liquidus T, ° C. 1157 1151 1154 1158 1172 1163 11621166 1164 1161 Delta T, ° C. 69 54 52 54 65 54 51 50 50 53 ExamplesComponents (wt %) 132 133 134 135 136 137 138 139 140 141 SiO₂ 59.9760.09 60.21 60.00 60.57 59.80 59.75 59.65 59.60 59.55 Al₂O₃ 12.97 13.0013.02 12.50 13.10 12.25 12.25 12.25 12.25 12.25 CaO 22.09 22.13 22.1823.70 22.31 22.60 22.85 23.35 23.60 23.85 MgO 2.70 2.50 2.30 1.90 1.703.10 2.90 2.50 2.30 2.10 TiO₂ 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.101.10 1.10 Na₂O — — — — — 0.30 0.30 0.30 0.30 0.30 Li₂O 0.90 0.90 0.900.90 0.90 0.60 0.60 0.60 0.60 0.60 Fe₂O₃ 0.25 0.25 0.25 0.25 0.25 — — —— — B₂O₃ — — — — — — — — — — RO (CaO + MgO) 24.79 24.63 24.48 25.6024.01 25.70 25.75 25.85 25.90 25.95 SiO₂/CaO 2.71 2.71 2.71 2.53 2.712.64 2.61 2.57 2.52 2.50 SiO₂/RO 2.42 2.44 2.46 2.34 2.52 2.33 2.32 2.312.30 2.29 SiO₂/Al₂O₃ 4.62 4.62 4.82 4.80 4.62 4.88 4.88 4.87 4.87 4.86Al₂O₃/CaO 0.59 0.59 0.59 0.53 0.59 0.54 0.54 0.52 0.52 0.51 SiO₂ + Al₂O₃72.87 73.09 73.23 72.50 73.67 72.05 72.00 71.90 71.85 71.80 R2O + RO +B₂O₃ 25.69 25.53 25.38 26.50 24.91 26.60 26.65 26.75 26.80 26.85 (Si +Al)/(R2O + RO + B) 2.33 2.86 2.89 2.74 2.96 2.71 2.70 2.69 2.68 2.67SiO₂ − RO 35.18 35.46 35.73 34.40 36.56 34.10 34.00 33.80 33.7 33.60Al₂O₃/RO 0.47 0.53 0.53 0.49 0.55 0.47 0.48 0.47 0.47 0.47 Log3 FT, ° C.1219 1223 1233 1239 1239 1240 1236 1236 1238 1234 Liquidus T, ° C. 11601155 1142 1139 1141 1156 1156 1159 1167 1173 Delta T, ° C. 59 68 91 10098 94 80 77 71 61 Examples Components (wt %) 142 143 144 145 146 147 148149 150 151 SiO₂ 59.50 60.00 59.95 59.90 59.85 60.21 60.33 60.75 60.2159.71 Al₂O₃ 12.25 12.40 12.40 12.40 12.0 12.24 12.27 12.35 13.02 13.24CaO 24.10 22.05 23.30 23.55 23.80 22.34 22.39 22.55 22.52 22.90 MgO 1.902.30 2.10 1.90 1.70 2.50 2.30 1.70 2.50 2.50 TiO₂ 1.10 1.10 1.10 1.101.10 1.50 1.50 1.50 0.50 0.50 Na₂O 0.30 — — — — — — — — — Li₂O 0.60 0.900.90 0.90 0.90 0.90 0.90 0.90 1.00 0.90 Fe₂O₃ — 0.25 0.25 0.26 0.25 0.250.25 0.25 0.25 0.25 B₂O₃ — — — — — — — — — — RO (CaO + MgO) 26.00 24.3525.40 25.45 25.50 24.84 24.69 24.25 25.02 25.40 SiO₂/CaO 2.47 2.72 2.572.54 2.51 2.70 2.69 2.69 2.67 2.61 SiO₂/RO 2.29 2.46 2.36 2.35 2.35 2.422.44 2.51 2.41 2.35 SiO₂/Al₂O₃ 4.86 4.84 4.83 4.83 4.99 4.92 4.92 4.924.62 4.51 Al₂O₃/CaO 0.51 0.56 0.53 0.53 0.50 0.55 0.55 0.55 0.58 0.58SiO₂ + Al₂O₃ 71.75 72.40 72.35 72.30 71.85 72.45 72.60 73.10 73.23 72.95R2O + RO + B₂O₃ 26.90 25.23 26.30 26.35 26.40 25.74 25.59 25.15 26.0226.30 (Si + Al)/(R2O + RO + B) 2.67 2.87 2.75 2.74 2.72 2.81 2.83 2.912.81 2.77 SiO₂ − RO 33.50 35.65 36.55 34.45 34.35 35.37 35.64 36.5035.19 34.31 Al₂O₃/RO 0.47 0.51 0.53 0.49 0.47 0.49 0.50 0.50 0.52 0.52Log3 FT, ° C. 1234 1230 1231 1224 1224 1215 1231 1240 1231 1227 LiquidusT, ° C. 1181 1146 1152 1156 1156 1162 1160 1166 1143 1142 Delta T, ° C.53 84 79 68 68 53 71 74 88 85 Examples Components (wt %) 152 153 154 155156 157 158 159 160 161 162 SiO₂ 59.46 60.02 60.26 60.14 60.10 60.2360.10 60.23 60.14 60.05 60.05 Al₂O₃ 13.24 12.35 12.40 12.37 13.00 12.2513.00 12.25 12.37 12.98 12.98 CaO 23.15 23.35 23.45 23.40 22.15 23.3622.15 23.36 23.40 22.14 22.14 MgO 2.50 2.54 2.55 2.54 2.50 2.50 2.502.50 2.54 3.12 3.12 TiO₂ 0.50 0.50 0.51 0.51 1.10 0.51 1.10 0.51 0.510.55 0.55 Na₂O — — — — — — — — — — — Li₂O 0.90 1.00 0.60 0.80 0.90 0.900.90 0.90 0.80 0.91 0.91 Fe₂O₃ 0.25 0.23 0.23 0.23 0.25 0.25 0.25 0.250.23 0.25 0.25 B₂O₃ — — — — — — — — — — — RO (CaO + MgO) 26.65 25.8926.00 25.94 24.65 25.86 24.65 25.86 25.94 25.26 25.26 SiO₂/CaO 2.57 2.572.57 2.57 2.71 2.58 2.71 2.58 2.57 2.71 2.71 SiO₂/RO 2.32 2.32 2.32 2.322.44 2.33 2.44 2.33 2.32 2.38 2.38 SiO₂/Al₂O₃ 4.49 4.86 4.89 4.86 4.624.92 4.62 4.92 4.86 4.63 4.63 Al₂O₃/CaO 0.57 0.53 0.53 0.53 0.59 0.520.59 0.52 0.53 0.59 0.59 SiO₂ + Al₂O₃ 72.70 72.37 72.66 72.51 73.1072.48 73.10 72.48 72.51 73.03 73.03 R2O + RO + B₂O₃ 26.50 26.85 26.6026.74 25.55 26.76 25.55 26.76 26.74 26.17 26.17 (Si + Al)/(R2O + RO + B)2.74 2.70 2.73 2.71 2.86 2.71 2.86 2.71 2.71 2.79 2.79 SiO₂ − RO 33.8134.13 34.26 34.20 34.45 34.37 35.45 34.44 34.20 34.79 34.79 Al₂O₃/RO0.52 0.48 0.48 0.48 0.53 0.47 0.53 0.47 0.48 0.51 0.51 Log3 FT, ° C.1226 1209 1230 1219 1235 1220 1237 1224 1219 1219 1223 Liquidus T, ° C.1147 1159 1158 1159 1133 1160 1136 1158 1159 1164 1163 Delta T, ° C. 7950 72 60 102 60 101 66 60 55 60

TABLE 14 Type 4 Glasses Examples Components (wt %) 163 164 165 166 167168 169 SiO₂ 58.30 58.20 58.10 58.15 58.15 58.00 58.25 Al₂O₃ 13.03 13.0313.03 13.20 13.33 13.03 13.33 CaO 23.54 23.64 23.74 22.85 23.39 23.8423.29 MgO 2.50 2.50 2.50 2.55 2.50 2.50 2.50 TiO₂ 0.50 0.50 0.50 1.100.50 0.50 0.50 Li₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.90 ZnO 1.00 1.001.00 1.00 1.00 1.00 1.00 Fe₂O₃ 0.23 0.23 0.23 0.25 0.23 0.23 0.23 B₂O₃ —— — — — — — RO (CaO + MgO) 26.04 26.14 26.24 25.40 25.89 26.34 25.79SiO₂/CaO 2.48 2.46 2.45 2.54 2.49 2.43 2.50 SiO₂/RO 2.24 2.23 2.21 2.292.25 2.20 2.26 SiO₂/Al₂O₃ 4.47 4.47 4.46 4.41 4.36 4.45 4.37 Al₂O₃/CaO0.55 0.55 0.55 0.58 0.57 0.55 0.57 SiO₂ + Al₂O₃ 71.33 71.23 71.13 71.3571.48 71.03 71.58 R2O + RO + B₂O₃ 26.94 27.04 27.14 26.30 26.79 27.2426.69 (Si + Al)/(R2O + RO + B) 2.65 2.63 2.62 2.71 2.67 2.61 2.68 SiO₂ −RO 32.26 32.06 31.86 32.75 32.26 31.66 32.46 Al₂O₃/RO 0.50 0.50 0.500.52 0.51 0.49 0.52 Log3 FT, ° C. 1204 1205 1206 1207 1208 1208 1213Liquidus T, ° C. 1147 1148 1144 1136 1152 1152 1146 Delta T, ° C. 57 5762 71 56 56 67

TABLE 15 Type 4 Glasses Examples Components (wt %) 170 171 172 173 174175 SiO₂ 58.00 58.10 57.35 57.95 59.61 59.47 Al₂O₃ 13.03 13.63 13.2013.20 12.16 12.16 CaO 23.84 23.14 23.65 24.05 23.50 24.22 MgO 2.50 2.502.55 2.55 2.50 1.90 TiO₂ 0.50 0.50 1.10 1.10 1.10 1.10 Li₂O 0.90 0.900.90 0.90 0.45 0.45 ZnO 1.00 1.00 1.00 1.00 0.45 0.45 Fe₂O₃ 0.23 0.230.25 0.25 — — B₂O₃ — — — — — — RO (CaO + MgO) 26.34 25.64 26.20 26.6026.00 26.12 SiO₂/CaO 2.43 2.51 2.42 2.41 2.54 2.46 SiO₂/RO 2.20 2.262.19 2.18 2.29 2.28 SiO₂/Al₂O₃ 4.45 4.26 4.34 4.39 4.90 4.89 Al₂O₃/CaO0.55 0.59 0.56 0.55 0.52 0.50 SiO₂ + Al₂O₃ 71.03 71.73 70.55 71.15 71.7771.63 R2O + RO + B₂O₃ 27.24 26.54 27.10 27.50 26.45 26.57 (Si +Al)/(R2O + RO + B) 2.61 2.70 2.60 2.60 2.71 2.70 SiO₂ − RO 31.66 32.4631.15 31.30 33.61 33.35 Al₂O₃/RO 0.49 0.53 0.50 0.50 0.47 0.47 Log3 FT,° C. 1208 1212 1195 1195 1229 1218 Liquidus T, ° C. 1149 1157 1141 11401154 1159 Delta T, ° C. 59 55 54 55 75 59

TABLE 16 Type 5 Glasses Example Components (wt %) 176 177 SiO₂ 59.0058.70 Al₂O₃ 12.00 11.90 CaO 22.50 22.4 MgO 3.40 3.40 TiO₂ 1.00 1.00 Na₂O0.90 0.90 ZnO 1.00 1.50 K₂O — — Fe₂O₃ 0.20 0.20 B₂O₃ — — RO 25.90 25.80SiO₂/CaO 2.62 2.62 SiO₂/RO 2.28 2.28 SiO₂/Al₂O₃ 4.92 4.93 Al₂O₃/CaO 0.530.53 SiO₂ + Al₂O₃ 71.00 70.60 R2O + RO + B₂O₃ 26.80 26.70 (Si + Al)/2.65 2.64 (R2O + RO + B) SiO₂ − RO 33.10 32.90 Al₂O₃/RO 0.46 0.46 Log3FT ° C. 1234 1231 Liquidus T ° C. 1175 1181 Delta(T3-TL) ° C. 59 50

TABLE 17 Type 6 Glasses Examples Components (wt %) 178 179 180 181 182183 184 185 186 187 SiO₂ 58.00 58.10 58.30 57.90 58.11 57.60 58.50 57.8058.00 57.80 Al₂O₃ 13.03 13.03 13.03 13.23 13.36 13.23 12.76 13.43 13.0313.03 CaO 23.84 23.74 23.54 23.74 23.40 23.84 23.61 23.64 23.84 23.84MgO 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 TiO₂ 0.50 0.500.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 Na₂O — — — — — 0.10 — — — — K₂O— — — — — — — — — — Li₂O 0.90 0.90 0.90 0.90 0.90 0.80 0.90 0.90 0.900.90 Fe₂O₃ 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 B₂O₃ 1.001.00 1.00 1.00 1.00 1.20 1.00 1.00 1.00 1.20 RO (CaO + MgO) 26.34 26.2426.04 26.24 25.90 26.34 26.11 26.14 26.34 26.34 SiO₂/CaO 2.43 2.45 2.482.44 2.48 2.42 2.48 2.45 2.43 2.42 SiO₂/RO 2.20 2.21 2.24 2.21 2.24 2.192.24 2.21 2.20 2.19 SiO₂/Al₂O₃ 4.45 4.46 4.47 4.38 4.35 4.35 4.58 4.304.45 4.44 Al₂O₃/CaO 0.55 0.55 0.55 0.56 0.57 0.55 0.54 0.57 0.55 0.55SiO₂ + Al₂O₃ 71.03 71.13 71.33 71.13 71.47 70.83 71.26 71.23 71.03 70.83R2O + RO + B₂O₃ 28.24 28.14 27.94 28.14 27.80 28.44 28.01 28.04 28.2428.44 (Si + Al)/(R2O + RO + B) 2.52 2.53 2.55 2.53 2.57 2.49 2.54 2.542.52 2.49 SiO₂ − RO 31.66 31.86 32.26 31.66 32.21 31.26 32.39 31.6631.66 31.46 Al₂O₃/RO 0.49 0.50 0.50 0.50 0.52 0.50 0.49 0.51 0.49 0.49Log3 FT, ° C. 1192 1194 1195 1195 1196 1196 1197 1197 1198 1198 LiquidusT, ° C. 1137 1135 1140 1137 1133 1133 1139 1139 1138 1135 Delta T, ° C.55 59 55 58 63 63 58 58 60 63

TABLE 18 Type 6 Glasses Examples Components (wt %) 188 189 190 191 192193 194 195 196* 197* SiO₂ 58.00 57.90 58.15 58.25 58.00 58.10 58.3058.20 58.74 58.64 Al₂O₃ 13.43 13.43 13.33 13.33 13.63 13.63 13.03 13.0313.05 13.15 CaO 23.44 23.54 23.39 23.29 23.24 23.14 23.54 23.64 22.9722.97 MgO 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.36 2.36 TiO₂ 0.500.50 0.50 0.50 0.50 0.50 0.50 0.50 0.49 0.49 Na₂O — — — — — — — — — —K₂O — — — — — — — — 0.09 0.09 Li₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.900.90 0.91 0.91 Fe₂O₃ 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.29 0.29B₂O₃ 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 RO (CaO + MgO)25.94 26.04 25.89 25.79 25.74 25.64 26.04 26.14 25.33 25.33 SiO₂/CaO2.47 2.45 2.49 2.51 2.50 2.51 2.48 2.46 2.56 2.55 SiO₂/RO 2.24 2.22 2.252.26 2.25 2.27 2.24 2.23 2.32 2.32 SiO₂/Al₂O₃ 4.32 4.31 4.36 4.37 4.264.26 4.47 4.47 4.50 4.46 Al₂O₃/CaO 0.57 0.57 0.57 0.57 0.59 0.59 0.550.55 0.57 0.57 SiO₂ + Al₂O₃ 71.43 71.33 71.48 71.58 71.63 71.73 71.3371.23 71.79 71.79 R2O + RO + B₂O₃ 27.84 27.94 27.79 27.69 27.14 27.5427.94 28.04 27.33 27.33 (Si + Al)/(R2O + RO + B) 2.57 2.55 2.57 2.592.64 2.60 2.55 2.54 2.63 2.63 SiO₂ − RO 32.06 31.86 32.26 32.46 32.2632.46 32.26 32.06 33.41 33.31 Al₂O₃/RO 0.51 0.52 0.51 0.52 0.53 0.530.50 0.50 0.52 0.52 Log3 FT, ° C. 1202 1203 1203 1202 1207 1212 12001201 1210 1209 Liquidus T, ° C. 1139 1137 1136 1145 1144 1146 1132 11371145 1151 Delta T, ° C. 63 66 67 57 63 66 68 64 65 58 ExamplesComponents (wt %) 198* 199 200 201 202 203 204 205 206 207 SiO₂ 58.6458.75 57.80 57.60 57.60 57.60 58.50 58.40 58.30 58.40 Al₂O₃ 12.95 12.9313.23 13.23 13.23 13.03 12.76 12.76 13.03 13.03 CaO 22.87 22.93 23.8423.84 23.84 24.04 23.61 23.71 23.54 23.44 MgO 2.36 2.36 2.50 2.50 2.502.50 2.50 2.50 2.50 2.50 TiO₂ 0.49 0.50 0.50 0.50 0.50 0.50 0.50 0.500.50 0.50 Na₂O — 0.04 — — 0.20 0.20 — — — — K₂O 0.09 0.10 — — — — — — —— Li₂O 0.91 0.90 0.90 0.90 0.70 0.70 0.90 0.90 0.90 0.90 Fe₂O₃ 0.29 0.290.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 B₂O₃ 1.00 1.20 1.00 1.20 1.201.20 1.00 1.00 1.00 1.00 RO (CaO + MgO) 25.23 25.29 26.34 26.34 26.3426.54 26.11 26.21 26.04 25.94 SiO₂/CaO 2.56 2.56 2.42 2.42 2.42 2.402.48 2.46 2.48 2.49 SiO₂/RO 2.32 2.32 2.19 2.19 2.19 2.17 2.24 2.23 2.242.25 SiO₂/Al₂O₃ 4.53 4.54 4.37 4.35 4.35 4.37 4.58 4.58 4.47 4.48Al₂O₃/CaO 0.57 0.56 0.55 0.55 0.55 0.54 0.54 0.54 0.55 0.56 SiO₂ + Al₂O₃71.59 71.68 71.03 70.83 70.83 70.63 71.26 71.16 71.33 71.43 R2O + RO +B₂O₃ 27.23 27.53 28.24 28.44 28.44 28.64 28.01 28.11 27.94 27.84 (Si +Al)/(R2O + RO + B) 2.63 2.60 2.51 2.49 2.49 2.47 2.54 2.53 2.55 2.57SiO₂ − RO 33.41 33.46 31.46 31.26 31.26 31.06 32.39 32.19 32.26 32.36Al₂O₃/RO 0.51 0.51 0.50 0.50 0.50 0.49 0.49 0.49 0.50 0.51 Log3 FT, ° C.1204 1210 1201 1200 1208 1201 1202 1203 1201 1208 Liquidus T, ° C. 11421127 1126 1125 1135 1145 1141 1145 1138 1137 Delta T, ° C. 62 83 75 7573 56 61 58 63 71 Examples Components (wt %) 208 209 210 211 212 213 214215 216 217 SiO₂ 58.15 58.25 58.70 58.00 57.60 58.61 58.61 58.00 58.4058.40 Al₂O₃ 13.33 13.33 12.75 13.03 13.03 12.16 12.16 13.23 13.36 13.03CaO 23.39 23.29 23.50 23.84 24.04 23.50 23.50 23.64 23.11 23.44 MgO 2.502.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 TiO₂ 0.50 0.50 0.50 0.500.50 1.10 1.10 0.50 0.50 0.50 Na₂O — — 0.60 — — — 0.45 — — — K₂O — — — —— — — — — — Li₂O 0.90 0.90 0.60 0.90 0.90 0.90 0.45 0.90 0.90 0.90 Fe₂O₃0.25 0.25 0.25 0.23 0.23 0.23 0.23 0.23 0.23 0.23 B₂O₃ 1.00 1.00 0.601.00 1.20 1.00 1.00 1.00 1.00 1.00 RO (CaO + MgO) 25.89 25.79 26.0026.34 26.54 26.00 26.00 26.14 25.61 25.94 SiO₂/CaO 2.49 2.50 2.50 2.432.40 2.49 2.49 2.45 2.52 2.49 SiO₂/RO 2.25 2.26 2.26 2.20 2.17 2.25 2.252.22 2.28 2.25 SiO₂/Al₂O₃ 4.36 4.37 4.60 4.45 4.42 4.82 4.82 4.38 4.374.48 Al₂O₃/CaO 0.57 0.57 0.54 0.55 0.54 0.52 0.52 0.56 0.58 0.56 SiO₂ +Al₂O₃ 71.48 71.58 71.45 71.03 70.63 70.77 70.77 71.23 71.76 71.43 R2O +RO + B₂O₃ 27.79 27.69 27.80 28.24 28.64 27.90 27.90 28.04 27.51 27.84(Si + Al)/(R2O + RO + B) 2.57 2.59 2.57 2.52 2.47 2.54 2.54 2.54 2.612.57 SiO₂ − RO 32.26 32.46 32.70 31.66 31.06 32.61 32.61 31.86 32.7932.46 Al₂O₃/RO 0.51 0.52 0.49 0.49 0.49 0.47 0.47 0.51 0.52 0.50 Log3FT, ° C. 1197 1200 1216 1202 1194 1201 1227 1201 1204 1201 Liquidus T, °C. 1130 1134 1160 1137 1142 1142 1159 1135 1133 1136 Delta T, ° C. 67 6656 65 52 59 68 66 71 65 Examples Components (wt %) 218 219 220 221 222223 224 225 226 227 SiO₂ 58.50 58.60 58.00 58.10 58.10 58.70 58.70 58.7058.61 58.40 Al₂O₃ 13.03 13.03 13.63 13.23 13.43 12.75 12.35 12.35 12.1612.76 CaO 23.34 23.24 23.24 23.54 23.34 23.50 23.50 23.50 23.50 23.71MgO 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 TiO₂ 0.50 0.500.50 0.50 0.50 0.50 0.50 0.50 1.10 0.50 Na₂O — — — — — 0.30 0.60 0.30 —— K₂O — — — — — — — — — — Li₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.60 0.900.90 0.90 Fe₂O₃ 0.23 0.23 0.23 0.23 0.23 0.25 0.25 0.25 0.23 0.23 B₂O₃1.00 1.00 1.00 1.00 1.00 0.60 1.00 1.00 1.00 1.00 RO (CaO + MgO) 25.8425.74 25.74 26.04 25.84 26.00 26.00 26.00 26.00 26.21 SiO₂/CaO 2.51 2.512.50 2.47 2.49 2.50 2.50 2.50 2.49 2.46 SiO₂/RO 2.26 2.28 2.25 2.23 2.252.26 2.26 2.26 2.25 2.23 SiO₂/Al₂O₃ 4.49 4.50 4.26 4.39 4.33 4.60 4.754.75 4.82 4.58 Al₂O₃/CaO 0.56 0.56 0.59 0.56 0.58 0.54 0.53 0.53 0.520.54 SiO₂ + Al₂O₃ 71.53 71.63 71.63 71.33 71.53 71.45 71.05 71.05 70.7771.16 R2O + RO + B₂O₃ 27.74 27.64 27.64 27.94 27.74 27.80 28.20 28.2027.90 28.11 (Si + Al)/(R2O + RO + B) 2.58 2.59 2.59 2.55 2.58 2.57 2.522.52 2.54 2.53 SiO₂ − RO 32.66 32.86 32.26 32.06 32.26 32.70 32.70 32.7032.61 32.19 Al₂O₃/RO 0.50 0.51 0.53 0.51 0.52 0.49 0.48 0.48 0.47 0.49Log3 FT, ° C. 1204 1204 1206 1199 1204 1204 1207 1202 1194 1194 LiquidusT, ° C. 1133 1135 1136 1133 1134 1153 1157 1149 1141 1144 Delta T, ° C.71 69 70 63 70 51 50 53 53 50 Examples Components (wt %) 228 229 230 231232 233 234 235 236 237 SiO₂ 58.80 57.60 58.11 58.91 58.11 58.30 58.2058.10 58.70 58.70 Al₂O₃ 12.46 13.03 13.36 12.16 13.36 13.03 13.03 13.0313.35 13.35 CaO 23.61 24.04 23.40 23.80 23.40 23.54 23.64 23.74 23.5023.50 MgO 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 TiO₂ 0.500.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 Na₂O — 0.10 — — — — — — — —K₂O — — — — — — — — — — Li₂O 0.90 0.80 0.90 0.90 0.90 0.90 0.90 0.900.90 0.60 Fe₂O₃ 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.25 0.25 B₂O₃1.00 1.20 1.00 1.00 1.00 1.00 1.00 1.00 0.30 0.60 RO (CaO + MgO) 26.1126.54 25.90 26.30 25.90 26.04 26.14 26.24 26.00 26.00 SiO₂/CaO 2.49 2.402.48 2.48 2.48 2.48 2.46 2.45 2.50 2.50 SiO₂/RO 2.25 2.17 2.24 2.24 2.242.24 2.23 2.21 2.26 2.26 SiO₂/Al₂O₃ 4.70 4.42 4.35 4.84 4.35 4.47 4.474.46 4.40 4.40 Al₂O₃/CaO 0.53 0.54 0.57 0.51 0.57 0.55 0.55 0.55 0.570.57 SiO₂ + Al₂O₃ 71.26 70.63 71.47 71.07 71.47 71.23 71.23 71.13 72.0572.05 R2O + RO + B₂O₃ 28.01 28.64 27.80 28.20 27.80 27.94 28.04 28.1427.20 27.20 (Si + Al)/(R2O + RO + B) 2.54 2.47 2.57 2.52 2.57 2.55 2.542.53 2.65 2.65 SiO₂ − RO 32.69 31.06 32.21 32.61 32.21 32.26 32.06 31.8632.70 32.70 Al₂O₃/RO 0.48 0.49 0.52 0.46 0.52 0.50 0.50 0.50 0.51 0.51Log3 FT, ° C. 1195 1196 1229 1216 1213 1202 1202 1205 1207 1224 LiquidusT, ° C. 1145 1145 1155 1148 1142 1136 1136 1137 1144 1145 Delta T, ° C.50 51 133 123 126 120 119 122 114 142 Examples Components (wt %) 238 239240 241 242 243 244 245 246 247 SiO₂ 58.11 58.20 59.53 59.61 59.11 59.1159.16 59.21 59.11 59.36 Al₂O₃ 13.36 13.23 12.25 12.16 12.16 12.16 12.1612.16 12.16 12.41 CaO 23.40 23.44 23.17 23.50 23.00 23.00 23.20 23.4023.50 23.60 MgO 2.50 2.50 2.52 2.50 2.50 2.50 2.25 2.00 2.00 2.00 TiO₂0.50 0.50 0.50 1.10 1.10 1.10 1.10 1.10 1.10 0.50 Na₂O — — — — — — — — —— K₂O — — — — — — — — — — Li₂O 0.90 0.90 0.80 0.45 0.90 0.90 0.90 0.900.90 0.90 Fe₂O₃ 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 B₂O₃1.00 1.00 1.00 0.45 1.00 1.00 1.00 1.00 1.00 1.00 RO (CaO + MgO) 25.9025.94 25.69 26.00 25.50 25.50 25.45 25.40 25.50 25.60 SiO₂/CaO 2.48 2.482.57 2.54 2.57 2.57 2.55 2.53 2.51 2.51 SiO₂/RO 2.24 2.24 2.32 2.29 2.322.32 2.32 2.33 2.32 2.32 SiO₂/Al₂O₃ 4.35 4.40 4.86 4.90 4.86 4.86 4.874.87 4.87 4.78 Al₂O₃/CaO 0.57 0.56 0.53 0.52 0.53 0.53 0.52 0.52 0.520.53 SiO₂ + Al₂O₃ 71.47 71.43 71.78 71.77 71.27 71.27 71.32 71.37 71.2771.77 R2O + RO + B₂O₃ 27.80 27.84 27.49 26.90 27.40 27.40 27.35 27.3027.40 27.50 (Si + Al)/(R2O + RO + B) 2.57 2.57 2.61 2.67 2.60 2.60 2.612.61 2.60 2.61 SiO₂ − RO 32.21 32.26 33.84 33.61 33.61 33.61 33.71 33.8133.61 33.76 Al₂O₃/RO 0.52 0.51 0.48 0.47 0.48 0.48 0.48 0.48 0.48 0.53Log3 FT, ° C. 1212 1204 1214 1230 1205 1216 1218 1213 1209 1216 LiquidusT, ° C. 1135 1135 1143 1155 1142 1143 1147 1153 1153 1153 Delta T, ° C.139 124 71 75 63 73 71 60 56 63 Examples Component (wt %) 248 249 250251 252 253 254 255 256 257 SiO₂ 59.31 59.36 59.41 59.11 59.16 59.2159.16 59.11 59.01 59.21 Al₂O₃ 12.56 12.51 12.46 12.16 12.16 12.16 12.2612.26 12.36 12.16 CaO 23.50 23.50 23.50 23.00 23.20 23.40 23.45 23.5023.50 23.50 MgO 2.00 2.00 2.00 2.50 2.25 2.00 2.50 2.50 2.50 2.50 TiO₂0.50 0.50 0.50 1.10 1.10 1.10 0.50 0.50 0.50 0.50 Na₂O — — — — — — — — —— K₂O — — — — — — — — — — Li₂O 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.900.90 0.90 Fe₂O₃ 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 B₂O₃1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 RO (CaO + MgO) 25.5025.50 25.50 25.50 25.45 25.40 25.95 26.00 26.00 26.00 SiO₂/CaO 2.52 2.532.53 2.57 2.55 2.53 2.52 2.52 2.51 2.52 SiO₂/RO 2.33 2.33 2.33 2.32 2.322.33 2.28 2.27 2.27 2.28 SiO₂/Al₂O₃ 4.72 4.75 4.77 4.86 4.87 4.87 4.834.82 4.77 4.87 Al₂O₃/CaO 0.53 0.53 0.53 0.53 0.52 0.52 0.52 0.52 0.530.52 SiO₂ + Al₂O₃ 71.87 71.87 71.87 71.27 71.32 71.37 71.42 71.37 71.3771.37 R2O + RO + B₂O₃ 27.40 27.40 27.40 27.40 27.35 27.30 27.85 27.9027.90 27.90 (Si + Al)/(R2O + RO + B) 2.62 2.62 2.62 2.60 2.61 2.61 2.562.56 2.56 2.56 SiO₂ − RO 33.81 33.86 33.91 33.61 33.71 33.81 33.21 33.1133.01 33.21 Al₂O₃/RO 0.49 0.49 0.49 0.48 0.48 0.48 0.47 0.47 0.48 0.47Log3 FT, ° C. 1220 1220 1220 1216 1214 1220 1209 1210 1210 1201 LiquidusT, ° C. 1153 1158 1155 1144 1147 1158 1150 1152 1152 1143 Delta T, ° C.67 62 65 72 67 62 59 58 58 58 Examples Components (wt %) 258 259 260 261262 263 264 265 266 267 SiO₂ 58.75 58.75 58.10 58.70 59.11 59.31 59.2154.60 56.75 57.85 Al₂O₃ 12.93 12.93 13.63 13.35 12.16 12.26 12.26 13.3513.20 12.45 CaO 22.93 22.93 23.14 23.50 23.50 22.30 23.40 24.55 23.9524.05 MgO 2.36 2.36 2.50 2.50 2.00 2.50 2.50 2.55 2.55 2.55 TiO₂ 0.500.50 0.50 0.50 1.10 0.50 0.50 0.35 1.10 0.55 Na₂O 0.14 0.24 — — — — —0.15 0.60 0.60 K₂O 0.10 0.10 — — — — — 0.55 — — Li₂O 0.80 0.70 0.90 0.300.90 0.90 0.90 0.30 0.30 0.30 Fe₂O₃ 0.29 0.29 0.23 0.25 0.23 0.23 0.230.28 0.25 0.35 B₂O₃ 1.20 1.20 1.00 0.90 1.00 1.00 1.00 3.00 1.40 1.30 F— — — — — — — 0.20 — — SrO — — — — — — — 0.12 — — RO (CaO + MgO) 25.2925.29 25.64 26.00 25.50 24.80 25.90 27.10 26.50 26.60 SiO₂/CaO 2.56 2.562.51 2.50 2.52 2.66 2.53 2.22 2.37 2.39 SiO₂/RO 2.32 2.32 2.27 2.26 2.322.39 2.29 2.01 2.14 2.35 SiO₂/Al₂O₃ 4.54 4.54 4.26 4.40 4.86 4.84 4.834.09 4.30 4.65 Al₂O₃/CaO 0.56 0.56 0.59 0.57 0.52 0.55 0.52 0.54 0.550.52 SiO₂ + Al₂O₃ 71.68 71.68 71.73 72.05 71.27 71.57 71.47 67.95 69.9571.30 R2O + RO + B₂O₃ 27.53 27.53 27.54 27.20 27.40 26.70 27.80 31.1028.80 28.80 (Si + Al)/(R2O + RO + B) 2.60 2.60 2.60 2.65 2.60 2.68 2.572.18 2.43 2.48 SiO₂ − RO 33.46 33.46 32.46 32.70 33.61 34.51 33.31 27.5030.25 31.25 Al₂O₃/RO 0.51 0.51 0.53 0.51 0.48 0.49 0.47 0.49 0.50 0.47Log3 FT, ° C. 1211 1218 1204 1239 1215 1209 1210 1187 1206 1208 LiquidusT, ° C. 1127 1129 1115 1143 1155 1148 1156 1133 1152 1154 Delta T, ° C.84 89 89 96 60 61 54 54 54 54 *compositions include 0.05 wt % SrO and0.08 wt % SO3

TABLE 19 Misc. Glasses Examples Components (wt %) 268 269 270 271 272SiO₂ 57.82 58.70 58.70 57.72 58.61 Al₂O₃ 11.80 13.35 13.35 11.80 12.16CaO 22.80 23.50 23.50 22.80 23.50 MgO 2.43 2.50 2.50 2.52 2.50 TiO₂ 1.070.50 0.50 1.07 1.10 Na₂O 0.87 — 0.90 0.87 — Li₂O — 0.30 0.30 — 0.30 ZnO— — — — 0.30 MnO 3.00 — — — 0.30 MnO₂ — — — 3.00 — Fe₂O₃ 0.22 0.25 0.250.22 0.23 B₂O₃ — 0.90 — — 1.00 RO 25.23 26.00 26.00 25.32 26.00 SiO₂/CaO2.54 2.50 2.50 2.53 2.49 SiO₂/RO 2.29 2.26 2.26 2.28 2.25 SiO₂/Al₂O₃4.90 4.40 4.40 4.89 4.82 Al₂O₃/CaO 0.52 0.57 0.57 0.52 0.52 SiO₂ + Al₂O₃69.62 72.05 72.05 69.52 70.77 RO2 + RO + B₂O₃ 26.10 27.20 26.30 26.1927.30 (Si + Al)/ 2.67 2.65 2.74 2.65 2.59 (R2O + RO + B) SiO₂ − RO 32.5932.70 32.70 32.40 32.61 Al₂O₃/RO 0.47 0.51 0.51 0.47 0.47 Log3 FT, ° C.1219 1239 1241 1222 1223 Liquidus T, ° C. 1163 1143 1165 1161 1139 DeltaT, ° C. 52 96 76 61 94

TABLE 20 Production Glasses Examples Components (wt %) 273 274 275 276277 278 279 SiO₂ 57.07 57.21 56.94 56.68 56.71 56.53 55.97 Al₂O₃ 12.6912.77 12.72 12.68 12.95 12.84 12.68 CaO 23.91 24.15 24.00 24.11 24.5624.42 24.00 MgO 2.53 2.57 2.56 2.58 2.44 2.42 2.45 TiO₂ 1.09 1.12 1.121.09 1.07 1.07 1.05 Na₂O 0.89 0.90 0.87 0.90 0.92 0.92 0.88 K₂O 0.0600.050 0.050 0.060 0.070 0.060 0.060 Fe₂O₃ 0.255 0.271 0.255 0.263 0.2780.267 0.265 B₂O₃ 1.37 1.36 1.42 1.40 1.54 1.70 1.36 SO₃ 0.029 0.0320.032 0.031 0.028 0.024 0.025 SrO 0.040 0.040 0.050 0.050 0.050 0.0500.050 Cr₂O₃ 0.002 0.002 0.002 0.002 0.009 0.008 0.007 RO 26.44 26.7226.56 26.69 27.00 26.84 26.45 SiO₂/CaO 2.39 2.37 2.37 2.35 2.31 2.312.33 SiO₂/RO 2.16 2.14 2.14 2.12 2.10 2.11 2.12 SiO₂/Al₂O₃ 4.50 4.484.48 4.47 4.38 4.40 4.41 Al₂O₃/CaO 0.53 0.53 0.53 0.53 0.53 0.53 0.53SiO₂ + Al₂O₃ 69.76 69.98 69.66 69.36 69.66 69.37 68.65 RO2 + RO + B₂O₃28.96 29.25 29.11 29.25 29.74 29.73 28.96 (Si + Al)/(R2O + RO + B) 2.412.39 2.39 2.37 2.34 2.33 2.37 SiO₂ − RO 30.63 30.49 30.38 29.99 29.7129.69 29.52 Al₂O₃/RO 0.48 0.48 0.48 0.48 0.48 0.48 0.48 Log3 FT, ° C.1214 1217 1203 1212 1212 Liquidus T, ° C. 1147 1134 1145 1147 1134 DeltaT, ° C. 67 83 58 65 76 Examples Components (wt %) 280 281 282 283 284285 SiO₂ 56.70 56.66 56.63 56.54 56.43 56.61 Al₂O₃ 12.91 12.86 12.8512.79 12.75 12.83 CaO 24.61 24.53 24.69 24.53 24.44 25.24 MgO 2.54 2.562.60 2.54 2.54 2.55 TiO₂ 1.10 1.09 0.94 0.94 1.09 1.20 Na₂O 0.91 0.900.93 0.90 0.90 0.92 K₂O 0.060 0.060 0.070 0.070 0.050 0.050 Fe₂O₃ 0.2600.265 0.267 0.268 0.270 0.279 B₂O₃ 1.32 1.15 1.34 1.27 1.24 1.29 SO₃0.018 0.020 0.018 0.016 0.014 0.016 SrO 0.040 0.040 0.040 0.040 0.0400.040 Cr₂O₃ 0.004 0.004 0.003 0.002 0.008 0.004 RO 27.15 27.09 27.2927.07 26.98 27.79 SiO₂/CaO 2.30 2.31 2.29 2.30 2.31 2.24 SiO₂/RO 2.092.09 2.08 2.09 2.09 2.04 SiO₂/Al₂O₃ 4.39 4.41 4.41 4.42 4.43 4.41Al₂O₃/CaO 0.52 0.52 0.52 0.52 0.52 0.51 SiO₂ + Al₂O₃ 69.61 69.52 69.4869.33 69.18 69.44 RO₂ + RO + B₂O₃ 29.64 29.41 29.83 29.51 29.39 30.28(Si + Al)/(R2O + RO + B) 2.35 2.36 2.33 2.35 2.35 2.29 SiO₂ − RO 29.5529.57 29.34 29.47 29.45 28.82 Al₂O₃/RO 0.48 0.47 0.47 0.47 0.47 0.46Log3 FT, ° C. 1213 1214 Liquidus T, ° C. 1149 1158 Delta T, ° C. 64 55

TABLE 21 Summary Sheet Type 1 Glasses Type 2 Glasses Type 3 Glasses Type4 Glasses Type 5 Glasses Type 6 Glasses Low High Low High Low High LowHigh Low High Low High RO (CaO + MgO) 26.30 27.05 24.80 27.56 24.0126.70 25.40 26.60 25.80 25.90 25.29 26.60 SiO₂/CaO 2.35 2.47 2.20 2.552.39 2.71 2.41 2.54 2.62 2.62 2.22 2.66 SiO₂/RO 2.13 2.23 1.96 2.29 2.162.52 2.18 2.29 2.28 2.28 2.01 2.39 SiO₂/Al₂O₃ 4.25 4.84 3.79 4.76 4.304.99 4.26 4.90 4.92 4.93 4.09 4.90 Al₂O₃/CaO 0.51 0.58 0.51 0.59 0.500.59 0.50 0.59 0.53 0.53 0.51 0.59 SiO₂ + Al₂O₃ 70.85 71.86 66.10 70.9571.05 73.67 71.03 71.73 70.60 71.00 67.95 72.05 R2O + RO + B₂O₃ 27.2027.95 28.15 32.79 25.15 27.60 26.30 27.50 26.70 26.80 26.70 31.10 (Si +Al)/(R2O + RO + B) 2.55 2.64 2.02 2.67 2.30 2.96 2.60 2.71 2.64 2.652.18 2.68 SiO₂ − RO 30.55 32.55 26.50 32.55 30.95 36.56 31.15 33.6132.90 33.10 27.50 33.91 Al₂O₃/RO 0.46 0.52 0.46 0.56 0.47 0.53 0.47 0.530.46 0.46 0.46 0.53

TABLE 22 Summary Sheet Types 1 &, 3–5, Glasses Types 2 & 6 GlassesProduction Glasses Types 1 & 2 Glasses Types 3–6 Glasses (boron-free)(contains boron) (contains boron) Low High Low High Low High Low HighLow High RO (CaO + MgO) 24.80 27.56 24.01 26.70 24.01 26.90 24.80 27.5626.44 27.79 SiO₂/CaO 2.20 2.55 2.39 2.71 2.36 2.73 2.20 2.66 2.24 2.37SiO₂/RO 1.96 2.29 2.16 2.52 2.14 2.52 1.96 2.39 2.08 2.16 SiO₂/Al₂O₃3.79 4.84 4.26 4.99 4.26 4.99 3.79 4.90 4.38 4.50 Al₂O₃/CaO 0.51 0.590.50 0.59 0.50 0.59 0.51 0.59 0.51 0.53 SiO₂ + Al₂O₃ 66.10 71.45 70.6073.67 70.85 73.67 66.10 72.05 68.65 69.98 R2O + RO + B₂O₃ 27.20 32.7925.15 28.64 25.15 27.80 26.90 32.79 28.96 30.28 (Si + Al)/(R2O + RO + B)2.02 2.67 2.30 2.96 2.30 2.96 2.02 2.68 2.29 2.41 SiO₂ − RO 26.50 32.5530.95 36.56 30.55 36.56 26.50 33.91 28.82 30.63 Al₂O₃/RO 0.46 0.56 0.460.53 0.46 0.53 0.46 0.56 0.46 0.48

1. A glass composition comprising: SiO₂ 57 to 58.2 percent by weight;Al₂O₃ 12 to 13.7 percent by weight; CaO 23.5 to 24.5 percent by weight;MgO 2 to 3 percent by weight; TiO₂ 0.5 to 2 percent by weight; Na₂O 0 to1 percent by weight; Li₂O 0 to less than 0.1 percent by weight; Na₂O +K₂O + Li₂O 0 to 1 percent by weight; Fe₂O₃ 0.05 to 0.4 percent byweight; B₂O₃ 0 to 0.05 percent by weight; fluorine no greater than 0.30percent by weight;

wherein the glass composition has a log 3 forming temperature no greaterthan 1240° C., and the difference between the log 3 forming temperatureand the liquidus temperature is at least 50° C.
 2. A glass compositioncomprising: SiO₂ 57 to less than 59 percent by weight; Al₂O₃ 12 to 14percent by weight; CaO 23 to 25 percent by weight; MgO 1 to 3 percent byweight; TiO₂ 0 to 2 percent by weight; Na₂O 0 to 1.25 percent by weight;Li₂O 0 to less than 0.1 percent by weight; Na₂O + K₂O + Li₂O 0 to 1.25percent by weight; Fe₂O₃ up to 0.5 percent by weight; B₂O₃ 0 to 0.05percent by weight; fluorine no greater than 0.30 percent by weight;

wherein the glass composition has a log 3 forming temperature no greaterthan 1240° C., and the difference between the log 3 forming temperatureand the liquidus temperature is at least 50° C.
 3. The glass compositionaccording to claim 2, wherein the TiO₂ content is 0.5 to 1.5 percent byweight.
 4. The glass composition according to claim 2, wherein the glasscomposition is essentially free of B₂O₃.
 5. The glass compositionaccording to claim 2, wherein the Fe₂O₃ content is 0.1 to 0.4 percent byweight.
 6. The glass composition according to claim 2, wherein the ratioof SiO₂ to (CaO+MgO) is no greater than 2.55.
 7. The glass compositionaccording to claim 2, wherein the ratio of SiO₂ to (CaO+MgO) is from 1.9to 2.4.
 8. The glass composition according to claim 2, wherein (CaO+MgO)is from 26 to 28 percent by weight.
 9. The glass composition accordingto claim 2, wherein the composition is essentially free of Li₂O.
 10. Theglass composition according to claim 2, wherein (Na₂O+K₂O+Li₂O) is nogreater about 1.03 percent by weight.
 11. The glass compositionaccording to claim 2, wherein (Na₂O+K₂O+Li₂O) is no greater than 1percent by weight.
 12. The glass composition according to claim 2,wherein the difference between the log 3 forming temperature and theliquidus temperature is at least 60° C.
 13. The glass compositionaccording to claim 1 wherein the SiO₂ is less than 58 percent by weight.